the only way to accurately measure this is below. 1. use one car only, preferably with strong brakes. 2. get 4-6 different sets of tires and rims with different widths. 3. make sure tire hieght, brand and compound are exactly same. 4. run test several times per set of tires. 5. make sure the weather and temperatures are same. I can't think of anything else for controls. feel free to add
@mattymag2394
7 жыл бұрын
Amir Hussain I don't feel you need 4-6 different tire types. if I were to run the test I'd have 3 sets of identical rims for a vehicle. run 205s 225 and 245s of same tire (my old e36 bmw could take those 3 sizes). you should be able to see a corrolation if there is one. and to add a bonus fact I'd run the same sets on wet road to see if wider tires are worse for hydroplaning.
@mattymag2394
7 жыл бұрын
Amir Hussain I don't feel you need 4-6 different tire types. if I were to run the test I'd have 3 sets of identical rims for a vehicle. run 205s 225 and 245s of same tire (my old e36 bmw could take those 3 sizes). you should be able to see a corrolation if there is one. and to add a bonus fact I'd run the same sets on wet road to see if wider tires are worse for hydroplaning.
@mathieumichaud1193
7 жыл бұрын
Yes I agree that this was not the best way to look into this because he totally disregards the diameter of the tire and the difference in the sizes of brakes
@ThePwaifya
7 жыл бұрын
You're asking for lab conditions from a single engineer. The test isn't extremely accurate but the results are enough to conclude that tire width isn't the biggest factor in stopping distance, which is exactly what the experiment set out to do.
@papayaman123
7 жыл бұрын
I agree that each science experiment needs a constant but in this case using multiple tires for a single car could be a bit difficult unless Jason has a tire company in his pocket lol
@fredflintsone3850
7 жыл бұрын
what about doing a test with one vehicle and several different tyre widths. (just need a tyre shop to sponsor)
@EngineeringExplained
7 жыл бұрын
Yep, would be great to do!
@goatmonkey2112
7 жыл бұрын
An interesting idea from a guy who stops his car with his feet.
@Grayman222
7 жыл бұрын
As an AP1 S2000 owner who got very confused looking at tires and rims I would like this. AP1 and AP2 have different staggered widths and then the possibility of a square setup on handling?
@joshuavanmeter5494
6 жыл бұрын
fred flintsone that would be a true test
@GmanMilli
6 жыл бұрын
Ya, what about brake strength, ABS specifications, and tire slippage? Maybe low profile tires have more braking strength. So many variables, difficult to isolate to come up with sound conclusions. Limiting to one vehicle and just swap tires would be good.
@Ballacha
7 жыл бұрын
There are so many other factors impacting a vehicle's stopping distance… brake - determines how long it takes for your wheels to lock up suspension, tyre compound & tyre pressure - determine how hard or soft your tyre profile is overall. Softer means more grip and therefore shorter stopping distance and vice versa You can only get some accurate correlation when all these factors are considered.
@alphazuluz
5 жыл бұрын
I remember learning in physics that the only two variables that are at play with friction are the coefficient of friction of the surface(s) and the downward force applied. It blew my mind. Theoretically, the size of the contact patch means nothing. I had a long discussion with my physics teacher about this and why wider tires increase traction on cars. Apparently there is so much more at play within the tire/pavement interface that it nearly nullifies the theoretical aspect of the equation. It was still interesting to learn that if tires had no tread, didn’t deform, and you were driving on a perfectly flat, hard surface, the width of the tire wouldn’t matter at all. A 5mm wide tire would work just as well as a 345mm tire given the same vehicle weight. It still doesn’t seem to make sense.
@EngineeringExplained
7 жыл бұрын
Some people aren't stoked - that's no good! What I enjoyed about all of this information is that it's not exactly what I expected to happen. Sure, there are different variables when every vehicle tested is a completely different car, but I found it fascinating how little correlation there was to a vehicle's weight and stopping distance. Quite surprising seeing the Nissan Armarda (6000 lbs) braking in the same distance as a Mitsubishi weighing 2700 lbs less. Also fascinating that tire width didn't strongly correlate with stopping distance. Even if the vehicles tested are different, you can see that clearly there are more important factors for stopping distance than weight or width alone. If you think the point of the video was to say that tire width and vehicle weight don't matter, that's not the case (as explained here: kzitem.info/news/bejne/zISXmJuQh6Oeh20). The point was that if you're planning on modifying your car, and think that you need bigger wheels and tires first to get better performance, you might want to simply check the rubber you're using first, and then worry about tire width. While you'll make marginal differences in grip with width and weight changes, you can make massive improvements with a good tire swap (my Honda S2000 increased peak longitudinal braking grip by 0.3 g's, that's insane!). Hope everyone's having a great day!
@Incubuspaxs
7 жыл бұрын
Engineering Explained I liked it and it really does tell how important tyres are for your vehicle depending terrain and environment.
@famguy619
7 жыл бұрын
Don't try to please everyone, Jason. As your channel grows, you will have far more aggressive comments from people that want to harshly criticize you. Criticism, as you know, is good! I've been watching your channel since the second or third video, and I can tell you care for the comments. You care about what people say and you change a bit to make things better for us viewers. Don't mind those that judge the quality of video, because you will learn and improve off of some of their comments, as you always do. Great video again! I love the amount that I am able to learn from being a subscriber to you. P.S. I turn off my adblocker just for you :)
@ShawnDickens
7 жыл бұрын
Engineering Explained Summer tire rubber compound would be the most important factor with tread pattern second (other than where tread has large holes or tiny tread blocks that deflect easiest with load). The traction rating of AS and A will include the combination of compound and tread block effectiveness in providing grip.
@S13Egg
7 жыл бұрын
how grip = stopping power?
@Diode5
7 жыл бұрын
I think the data demonstrates that the engineers building these cars for the most part are putting on adequate brake, suspension and wheel size configurations to meet whatever minimum breaking distance safety standard they need to. The choice of a better tyre simply helps improve those results further.
@BrandenMcNabb
7 жыл бұрын
You did a very good job with the slideshow. Please don't ever do it again.
@matthewblainey4254
7 жыл бұрын
hahahaha R=0.25 would be the wet dream of any psycological study
@EngineeringExplained
7 жыл бұрын
Haha yeah, my girlfriend's a biologist and said that 0.25 can be publishable. Fascinating haha.
@rocknslope
7 жыл бұрын
R squared. Not R.
@drewren1231
7 жыл бұрын
If a class spends the first week trying to convince students that they're as scientific as hard sciences, then it's not science. Every social science class ever.
@peaj4812
7 жыл бұрын
Man I worked at a Biochemistry Lab for a while and my experiment needed an r^2 value of at least .95 or I had to redo it, but to be honest it was always above .98. But then again it was a simple experiment.
@matthewblainey4254
7 жыл бұрын
Pearson James yeah i study Biochem at uni! :) always a p
@panayotpopov6698
7 жыл бұрын
This video is meaningless, You don't isolate any of the properties that you are testing. Testing different tire widths on different cars tells you nothing. To find if the width of the tires has any effect you should measure the change in stopping distance for the same car with different tires. Same goes for everything else.
@Kalandaari
7 жыл бұрын
Different cars, different kind of tires (road tires vs off-road tires), ... This video is really bad.
@radix4801
7 жыл бұрын
Test one car, summer vs offroad vs all season tires. Same car, test all season narrow vs wider tires. See which change gives the biggest performance boost. Quicker, simpler, and more accurate.
@Conservator.
7 жыл бұрын
Jason I like your video's a lot but this one (lets say) the least of them. Because of all the different parameters (cars, weight, surface, tyre manufacturer, tyre type, pressure, …) you found only very weak correlations. That was no coincidence. The best (imho the only meaningful) comparison was the performance on- and off-road. The Dodge performing about worst on-road and best off-road really says it all. I would love to see a video of you testing your Honda on different tyre widths! Thanks anyway for your awesome vids!
@bluetarget
7 жыл бұрын
ya know the graph that shows weight/width to stopping distance? that normalizes the data to show exactly why width and weight don't matter nearly as much as compound and tire category. that's the whole point of the video. you don't need to isolate the variables to get to this conclusion. please take some math classes. all of you.
@mikeb1031
7 жыл бұрын
he is finding a trend
@sinewave999
7 жыл бұрын
You should actually make a video with your S2000 with wideass tires vs with oem tires
@URBANENGINEER
7 жыл бұрын
I thought the point of wide tires was cornering stability.
@JohnUnit
7 жыл бұрын
It helps the most with cornering, but also helps with lateral (acceleration and braking) grip.
@chrisallen8395
7 жыл бұрын
Lateral refers to cornering.
@atirrell
7 жыл бұрын
Lateral grip = holding forces perpendicular to direction of travel Longitudinal grip = holding forces parallel to direction of travel
@labradormcgraw2409
7 жыл бұрын
I've said it once, I'll say it again - this guy embodies everything that's great about KZitem. Unrivaled knowledge coupled with a natural talent for teaching... add to this the seldom-seen ability to include only what we really need to know, and what we have is an absolutely indispensable learning resource. The fact that, through KZitem, we get all that for free necessitates the burning question: why are we paying $$$$s for inferior quality tuition from college? Huge respect to EE!
@kinglimpang8067
7 жыл бұрын
Plot price of braking system against stopping distance please XD
@megaFINZ
7 жыл бұрын
I'm pretty sure stock brakes will outperform stock tires on most of the cars. If ABS is engaged during the emergency braking, then it means that brake applies more force than tire can handle, so it's the tire that is the limiting factor, not the brakes.
@gedasalekveravicius5466
7 жыл бұрын
I petsonaly think this is one of the best way of explaining, better than whiteboard. Also if youake animations about new invensions it would be even better. Like laferrari's intake or so. Thums up from me.
@Dylesxic
7 жыл бұрын
He's said in the past why he doesn't use animations. For the most part it's because of the amount of time added to each video in order to get good quality animations vs how many videos he can put out using his white board. Plus it's kind of his thing now, why would we take that away?
@wheelheroes7902
7 жыл бұрын
Despite some of the negative reactions I still think this was an interesting and enjoyable video. Now we know that tire compound is more important than width, it would be cool if you did a comparison with some vehicles with a fixed tire type but with different sizes, in width and diameter. starting from OEM and increasing the size till there are negative effects (because of higher weight, drag, price etc.). I look forward to that! Thanks and have a day! Greetings.
@BucketWheat
6 жыл бұрын
Yes... very much agree...on all points... Informative video, and great suggestion for "Part 2".. (-:
@Slider68
7 жыл бұрын
It is clear tire type has the largest impact on stopping grip (on specific surfaces) but once you take this out there may be additional relationships to discover in the data. For example I suspect you will see a slope of close to 1 when plotting weight/width vs stopping distance for a single tire family. If so this would suggest several additional relationships: 1. Increasing the ratio of weight to width in general worsens dry pavement stopping distance and vice versa. 2. Increasing tire width (without changing anything else) improves dry stopping distance. 3. Reducing the weight of a vehicle shortens dry pavement stopping distance and vice versa. The above predictions align well with what we experience when changing tire size and driving on dry pavement BUT wet pavement and snow/slush covered roads are totally different (opposite conclusions are typical).
@lundy6577
7 жыл бұрын
Why was Parker not invited ?
@Richyd7770
7 жыл бұрын
because Rob Dahm stole his invitation
@EngineeringExplained
7 жыл бұрын
And here I thought this was a drama free channel. 😂
@aDIYCarGuy
7 жыл бұрын
no one is immune
@Richyd7770
7 жыл бұрын
Oscar Thorpe no replacement hood and akward apology = no invite to tire events
@porkchopgaming8480
7 жыл бұрын
Because he was gonna bend their hoods not pay for it then insult them
@bradlywages
4 жыл бұрын
We tried this with a 91 mustang on a private test pad. 33 X 18.50 15 did not grip like 29 x 11.50 15. Same compound same day. 33s would break loose before the 29s would. Full contact patch was verified during the burnout and pressures were changed as needed. It came down to suspension set up, weight transfer weight over the tires. You have to have the weight in the right place to get the grip.
@1fastnigel
7 жыл бұрын
Awesome test! I would have liked to see tyre contact patch area and weight versus stopping distance. This would give more indication of how tire width and radius play into this.
@rahulkalvem5191
7 жыл бұрын
braking system(rotors, calipers, pads) depends a lot on stop distance
@SerendipitousProducts
6 жыл бұрын
That’s what i was going to post as well. Good to see someone did.
@optionedup
7 жыл бұрын
Wow. So many commenters here who seem to think they are very intelligent completely missed the point of this video. I'm going out on a limb here to say that Jason's goal in creating this video was not to create the ultimate tire test. It's possible he doesn't have the resources to conduct the comprehensive tire test some of you think he should have done. In addition, many comprehensive tire tests have already been conducted and he has nothing to gain by duplicating them. He had an opportunity to participate in a limited driving test of 27 vehicles. Instead of presenting the same boring feature comparison that all the other dozens of reviewers undoubtedly did after the event, he chose to stand out as different from the average reviewer by recording a limited amount of data and showing us how to draw useful conclusions from it. I learned a lot more from this video than I would have from a traditional auto review. I'm subscribed to this channel because of this unique perspective. Thank you for the work you did on this video.
@EngineeringExplained
7 жыл бұрын
+optionedup appreciate the thoughtfulness of your comment, glad you enjoyed the video!
@theripper121
7 жыл бұрын
Well if the point of this video is to answer the question that is contained in the thumbnail than no this video and all this data that was compiled is failing at answering said question. If you are simply asking if wider tires have more grip you would not be testing different types, sizes, brands, compounds, and cars. There are way too many variables that are changing from test to test. While this video gives some good information especially toward the end this video is not a good test for the stated question that was initially imposed. The data is certainly not bad but does not really correlate to the question that was posed. "So many commenters here who seem to think they are very intelligent completely missed the point of this video" Seems to me they aren't missing the point of the video if the point of the video was to answer the question in the thumbnail. Seems to me this video needs to be titled differently for that's not what was really tested through the parameters of this experiment.
@djd34d14
7 жыл бұрын
To me it's kind of like this: Think about an electronics publication. Say they have 5 computers that they used a day each. They decided to perform hard drive benchmarks from within 5 different operating systems. They then use the data from the different tests on the hard drives to comment on the speed of the whole computers. It's related, sure. But the relation is loose and the expirement didn't provide enough data to really prove anything.
@BucketWheat
6 жыл бұрын
I strongly agree with 'optionedup' that Jason is presenting some very useful information & data, and I appreciate Jason's work on all of this..!! But I also agree that to answer the specific question, all of the testing should have been done on a single vehicle, or maybe a group of 3 -- street, all-season, and off-road -- to show how vehicle design/structure also effects braking efficiency. Otherwise, you can't 'isolate' width as the differing factor. Does a 265 tire on the BMW stop faster than a 235 tire? and so on.
@xskinyx
6 жыл бұрын
Two very simple modifications would provide a ton of insight - 1. Divide tire width by weight (mm/lbs), not the other way around (lbs/mm). 2. Plot the weighted width on the x-axis and the stopping distance on the y-axis. The plot should read - "given a tire width (corrected for weight) what was the sample's stopping distance?" then look for a trend. Also, since you know the different tire types, you may want to calculate separate regressions for each type. Of course, I get your point. (Spoiler!) The type of tire is more important than the the width. And you can only get that across by showing the different types on the same plot.
@zuilok
7 жыл бұрын
There are way too many variables in these tests actual answers from experience: Do heavier cars have less grip? No they have more. (doesnt mean they stop faster) Do wider tires have more grip, in theory no, in actual life yes pretty much 100% of the time. Most important factor for tire grip? Tire compound.
@telewubby1961
7 жыл бұрын
example is the pressure of the caliper, the number of calipers, and the material of the rotors and pads.
@Klikkitse
7 жыл бұрын
Thank you captain obvious, zullok. If you watched any of Jason's other videos you'd know he knows all this and has educated us about that. If anything the title was a little misleading but I think it was meant to provoke thinking. Instead of finding out the obvious answer with five repeats over 25 different tires with the same car and suspension setup and tire pressure and outside temperature and .... Jason found out width isn't even half of the story. Active setup systems and tire compounds seem to account for most improvement in braking distance. This means that with the given (diverse!) real world data about cars in general he failed to reject null hypothesis. That is what you're supposed to take away from this video. He even goes out to point out the limitations of his dataset and I believe his numbers. If the actual research question was about tire width I'm pretty sure he would have used one of his other standard testing setups. I'm just overwhelmed by the number of people who took this for serious publishable research. Heck, he even says he doesn't know the weight of one of the vehicles he tested, why aren't people outraged about that if this is serious research?!
@megaFINZ
7 жыл бұрын
And what's the theory behind wider tires?
@djd34d14
7 жыл бұрын
If your take is the true take away, then imho the name of the video should be "which of these stock cars stops better?"... but the data doesn't support that either as there are modified vehicles in the test. I think the precedent set in the early days of this channel means many of us expect well thought out experiments whether the results data is publishable or not. This seems to be more of a fleeting thought he acted on while at a cool event.
@hawkdriver68
7 жыл бұрын
Djd34d1, ummm... yeah. If offered an opportunity like that, I'd jump on it and make something of it as well. I believe he implies as much also.
@EMETRL
6 жыл бұрын
The point of this video isn't to give a complete picture with statistically significant conclusions, it's mainly to show that there are plenty of misconceptions about the topic. He's already done case studies showcasing modern technology in improving braking distances, so he just had some fun with raw data and extrapolating what he could.
@horaciolopez7721
7 жыл бұрын
Screw the data! I am going to slap on some 315's all seasons for my stock 8th gen civic! Burn rice baby! 🔥🍚
@eddieb8678
7 жыл бұрын
Horacio Lopez 8th Gen Civics ftw
@levy5867
7 жыл бұрын
stick brembo decals to the calipers, it'll greatly improve the breaking distance on your rice. Trust me.
@eddieb8678
7 жыл бұрын
Stickers are +5 horsepower each!
@ZachPye
7 жыл бұрын
that's not rice, that is how you get a ticket
@bin1127
7 жыл бұрын
add more water when cooking?
@craigweis1675
4 жыл бұрын
Years ago Road and Track Magazine posted an article about tires ... the conclusion was wide tires have a shorter front to back footprints while narrower tires have a longer front to back footprints. The tires were driven over a glass panel and photographed from the bottom looking up at the rubber. The photos revealed that the surface area of 'rubber on the road' for wide or narrow tires is the same square cm on vehicles of the same weight.
@horrovac
7 жыл бұрын
In central/northern Europe, as well as in alpine regions, everybody uses summer and winter tyres. Only total cheapskates use all season. All season sucks in all seasons and is just marginally better than winter tyres in summer or summer tyres in winter. In the US, everybody apparently uses all season (which explains these comedy videos with cars sliding all over the place on icy roads), and I don't really get why. It's not like you're saving anything - sure, with winter/summer you have two sets of tyres, but they last twice as long. You need two sets of wheels, but they don't have to be alloys (lots of people use steel for winter tyres). You can have wider, grippier tyres in summer and narrower ones in winter, which don't suffer that much from aquaplaning and work better in snow and sludge. Also, you'll have a vastly superior performance in any season, and a huge advantage for your safety. AND you'll have a whole lotta more fun. Good tyres are the MOST important performance mod you can do for your car, and it's not expensive either.
@BirdiesGoCherp
2 жыл бұрын
All season tyres are actual really good, shitty tyres are shitty. All seasons are very good, check out tyre reviews.
@horrovac
2 жыл бұрын
@@BirdiesGoCherp I'm sorry but that is just not true. I wouldn't be talking like this if I did not know. OF COURSE i have checked out tyre reviews - most importantly the ones of the European car clubs. They do very thorough joint annual tyre reviews, both for summer and for winter tyres. And obviously their loyalty does not lie with suppliers or manufacturers but with their members only. They also do all-seasons, though I believe not regularly. Every time, the result is horrible. Some of them deliver performances almost on par with summer or winter tyres - the key word here is "or". Either one or another, but never both. Essentially, they are either summer tyres with a bit of snow-going capabilities, or winter tyres with a bit of summer rubber compound and a summer-ey thread profile. The better they are in summer, the more they suck in the winter and vice versa. Some of them offer a balanced performance, which actually is just another way of saying that they're equally horrible in both seasons. Whichever type you get, the one common thing they all have is that even the best performing ones for either seasons are never nearly as good as even mediocre summer or winter tyres. You can't cheat physics. The verdict of the tests is always the same: buy summer or winter tyres instead. If you don't have money, get the cheapest ones, they cost less than the non-horrible all seasons, perform better in both seasons, and last at least twice as long. They couldn't think of a good reason to use all-seasons, except that if for some unfathomable reason you MUST drive the same set of tyres all year round. And neither can I. Sure, to prevent fatal accidents, most people won't need the highest performance from their tyres most of the time. Until they do.
@BirdiesGoCherp
2 жыл бұрын
@@horrovac their latest all season reviews show incredible performance in the wet and on snow though.
@horrovac
2 жыл бұрын
@@BirdiesGoCherp not disputing that. They might even be just as good as mediocre winter tyres, because in essence that's what they actually are - winter tyres made slightly worse. The dry performance is going to totally suck, I could almost bet. I was not conteding that all-seasons were TOTALLY useless for everything, just that they're vastly inferior to a summer/winter combination in almost any measure - cost, performance, longevity etc...
@ParthGohil1
7 жыл бұрын
Asked this question to my physics teacher about 11 years ago, never got an answer then, but he did tell us that the formula for friction doesn't depend on area of contact (because molecular level contact can't really be calculated) instead it's dependent on load and on coefficient of friction (i.e type of tyre) while this data seems to be in relation to that I later found out that the width of the tyre is important during turns.
@johnbennett9030
7 жыл бұрын
Beautiful video. Good information. Totally answered things I had been wondering about. Thanks!
@tpsolidious
7 жыл бұрын
can you do a video on what is bearing the weight of the car ? Wheel bolts, The protruding center bore from the hub, or the clamping force of the bolts that create friction between the wheel and hub? how much pressure is applied when torqued down? diameter of the bolts?
@OmegaF77
7 жыл бұрын
"Do wider tyres have more grip?" *Tests with different vehicles including their weight rather than having one vehicle and testing with differ tyre widths and compounds.*
@mikebrown614
7 жыл бұрын
It would have been interesting to see what the R-values of the trend-lines would have been had you removed the upper and lower outliers from the calculation. That Ram PowerWagon and the BMW slewed the line dramatically.
@amolauliyan7318
7 жыл бұрын
hey ! engineering explained instead of plotting so much data try Buckingham theorem which will assist you in plotting a particular quantity vs another......have a nice day
@Oblithian
6 жыл бұрын
I imagine the answer is "obviously yes", but noting that "just because a car has wider tires than a different car, doesn't mean that's the only determining factor" (especially of braking distance). If every car had the same tire design and compound, and if the braking test was performed with narrow and wide tires, the braking would be better with likely no exception.
@MyRealName
7 жыл бұрын
I'd be ashamed as an engineer if I didn't use the universal metric system.
@LogiForce86
7 жыл бұрын
Plus you'll increase your world wide job chances as well by using the universal metric system.
@Garebare1
7 жыл бұрын
MyRealName I'm an engineering student and every company in the United States as well as American companies in foreign countries use imperial system so if you want to attend engineering courses in the U.S. Or work for U.S. Engineering firms, u must know the imperial system...you are mostly taught metric system in other courses like physics and chemistry courses and a mixture of metric and imperial in engineering courses
@hightower2537
7 жыл бұрын
we use both. and yes every engineer that i know prefers metric.
@Garebare1
7 жыл бұрын
Hightower I agree the metric system is a lot easier to compute with, however I find that I can visualize the imperial system better, for example I have a better idea on what a mile looks like than a km, I can visualize how fast 60 mph is but not really 60 kph
@patw52pb1
7 жыл бұрын
The shame is yours. As an engineer, you should be able to proficiently and accurately use any unit system, any scale, anywhere, anytime, for any reason or any specification. He used what was available as mentioned in the video. I really do not believe he is auditioning for a job world wide.
@Kixis
6 жыл бұрын
Since the comments mentions a lot of what I wanted to say already, I'll just add this since I didn't see this in the comments that I seen: fix your axis. X is independent and y is dependent. Stopping distance is a dependent variable and should be on the y axis.
@VforValenti
7 жыл бұрын
Well, you have applied really poorly the OLS Estimator. It is obvious that when, for example, you estimate (brake distance) = α + β*(tire width) + error, that error term contains for example weight that has great correlation with your regressor, ie tire width (it could be not only weight! Everything contained in error term, that has good correlation with your regressor could have the same effect: like for instance brake size, that you did not measure). So you do not have the most important assumption required to use OLSE: strict exogeneity; that is that in y=α+βx+ε, Ε(εi | all x's)=0 for all i. Not only your results have poor R^2, but, because of this, they are also completely meaningless. Just waste. (NOTE: some results had R^2 like 0.14? These don't even worth to be shown, even if you had ensured the validity of OLSE assumptions) You could use at least a multi-variable regression like: (brake distance) = α + β1*(weight) + β2*(tire width) + ε, for example. This way you extract the effect of weight in error to a new additional factor, so ε gets cleaner (not guaranteed clean enough though; check "omitted variable" problem for further info). Your outcomes would become stronger in R^2 and more serious. You have a great channel, and I appreciate it very much. I am telling this in really good faith, as a more statistics educated person. Hope my intentions will not be missapprehended. :-)
@SvenStadt
6 жыл бұрын
You just gave the conventional wisdom of things I've been told by my dad all my life, and he is a mechanic! Great videos. You're the only guy I would want to give me car advice. Thanks alot!
@EngineeringExplained
6 жыл бұрын
+SvenStadt Your Dad seems like a good dude, great to pass down car knowledge!
@lululombard
7 жыл бұрын
PLEASE. Use METRIC.
@herculesrockefeller2984
7 жыл бұрын
AMERICA 1ST! EVERYPLACE ELSE IS THE WORST!
@herculesrockefeller2984
7 жыл бұрын
+rossi23 You'll be singing a different tune after Glorious Leader Trump starts WW3
@BowYangJam
7 жыл бұрын
Use a calculator. It isn't that difficult.
@atirrell
7 жыл бұрын
You're watching an engineering video and you are concerned about units of measure...? Do you also want him to have this video translated into 27 different languages for you?
@emin86
7 жыл бұрын
SI units are the standard in engineering. Better not do the same mistake like the Mars Climate Orbiter. While NASA used the "International System of Units" (SI units using metric system), the navigation software made by Lockheed Martin used the outdated imperial system. No conversion was made, the space probe approached Mars to much (by around 100km, calculate in miles on your own) and the probe got destroyed. Would not happen if engineers would have used the standard units of engineering in the first place. But that's none of my business. As a European I don't pay taxes that financed this disaster. Plus, this channel is Engineering Explained, and yet no usage of SI units.
@skrrBOP
6 жыл бұрын
College physics kid here, trying to act smart but what i have learn is that for Force of friction (dry friction) Ff=µ*Fn, where µ is the coefficient of friction (depends on the materials-in this case rubber in tires and asphalt) and Fn is the normal force (in this case its mass*gravity) and by that you can come to the conclusion that the amount of surface between the asphalt and tires doesn't impact the force of friction, but the weight does, but you could ask why don't heavier cars stop faster? It's because that mass also impacts the impulse of the car which just nullifies with friction (in most cases). English is not my native language so i excuse myself if you spent time reading this and didn't understand a thing
@zzInFusioNzz
7 жыл бұрын
SI units please
@IBreiKeL
7 жыл бұрын
Why does it matter? The chart would look exactly the same.
@herculesrockefeller2984
7 жыл бұрын
FREEDUM UNITS RULE!!! America 1st!, Every place else is the worst!
@felixbelanger2659
7 жыл бұрын
I think tire pressure could have been interesting to see (while difficult to do at an event like this). I think the shape of the contact patch might have been more important than the actual width of the tires. Perhaps a test for the S2K?
@denistablica
7 жыл бұрын
I am sure you can make grafs with metric units parallel to imperial... at least for weight unit Mini Cooper?? Cooper is trim level not model. Thanks for the video
@coldblue32E
7 жыл бұрын
denistablica except it was a Cooper. All Countrymen are Coopers, so he wasn't wrong. In fact, they are all Cooper S's
@LarryReynolds591
7 жыл бұрын
A couple things: 1. R squared isn't the best number to look at for determining whether the relationship is statistically significant. A t-test in the Excel regression command would have been better. R squared values of 0.4 are pretty darn good for cross sectional data. 2. A regression of stopping distance on *both* weight and tire width would have told you if either of those factors mean something. You could also control for tire type with dummy variables. It would be great if you could provide the data for us to download!
@VforValenti
7 жыл бұрын
In a single variate regression, don't expect T-student test of the single regressor and F-test (R^2) to give different outcomes... Also, R^2 of 0.4 could mean bad or good fit, depending on the model... But a magnitude of R^2=0.14 is bad fit. Here the problem is other, and it is more serious. We have obvious violation of exogeneity... (omitted variableS problem). So your second advice is towards the right way.
@geriatrics9557
7 жыл бұрын
I've never had the highest likes on a comment
@c0d4041292
7 жыл бұрын
You got this, man!
@DrzAnt12
7 жыл бұрын
and hopefully you don't get it on some like hungry comment like this.
@BillCut
7 жыл бұрын
HAHAHHAHA your name is hilarious!!
@EngineeringExplained
7 жыл бұрын
The spotlight is all you!
@ThePrincess540
Жыл бұрын
Hey Engineering Explained, love your videos. Your videos inspired me to pursue engineering. You always bring so much insight and engineering knowledge into your videos, it’s great! Could you do a video on wider tires specifically on snowy or slushy conditions. Would this be similar to the off road stopping distance results?
@SgtKanyo
7 жыл бұрын
Do wider tires actually have more grip? Yes, because of a bigger tyre patch on the road surface. Case closed.
@IvanToman
7 жыл бұрын
Do narrower tyres have more grip? Yes, because of bigger pressure on the road. Case closed. When you take your argument and my argument into consideration, you will find out that it actually doesn't matter, and there are many more important factors that will determine grip, like tyre wear, tyre compound, tyre thread type and so on.
@Kizaoners1
7 жыл бұрын
If false then tell me why F1 cars have wide tires? especially this year...
@dewolf49
7 жыл бұрын
Bazsa Largely because the wider the tire, the softer you can make the compound without it collapsing the sidewall. The actual contact patch doesn't affect grip directly because friction is directly proportional to the normal force (i.e. the small the contact patch the higher the normal force and so the resulting friction is exactly the same, all else barred.) The size of the contact patch -does- affect wear, but not grip directly.
@herculesrockefeller2984
7 жыл бұрын
+Bazsa Wider tires are better for dry and sometimes light rain conditions. Skinny tires provide more grip in the snow and heavy rain where puddles form on the road. Then there's off road where the arguments never end, but skinny is typically better for shallow mud/snow while deep sand requires a wider tire, and the rock crawlers will argue all day long between wide vs skinny.. Wider tires are worse on fuel economy which could also be a factor depending on the situation. In races where different tire sizes are allowed, a car with less grip and skinnier tires could actually win against a car with better grip due to less pit stops etc. Everything's subjective.
@IvanToman
7 жыл бұрын
Narrow tyre is better in shallow snow, but in deep is wider tyre better because it doesn't sink that much. If vehicle sink through snow too much, it starts to plow too much snow with a bumper which slows it down and finally stops it completely. Wider tyres make vehicle to "float" over the snow better.
@TheRealEvilSink
7 жыл бұрын
Of course it does, but when you mount aftermarket rims and tires, you have to find optimal tire pressure for grip yourself. its quite easy, just measure if the tires have more heat in the middle or the sides of the tires and inflate/deflate accordingly. when the tire has the same temperature on the entire width of the contact patch, you have found your optimal tire pressure. (it may change a little with temperature, if its wet, etc, but you will get a good baseline.)
@itaytabib4665
7 жыл бұрын
technically, physics wise, friction has nothing to with contact area EDIT: yh that's not true
@ipodge1731
7 жыл бұрын
I wonder why so many people believe that wider tire means more grip. Tire company conspiracy?
@giorx5
7 жыл бұрын
Any test braking a car on dry tarmac and upgrading its tire width testing again, all the other componts remaining the same, makes your theory false. And the F1 cars of 2017 where all the drivers are ultra-excited about much less stopping distance vs the 2016 season cars. Even with harder compounds the grip from the wider tires is greatly improved, especially when braking.
@RandomGenera7ed
7 жыл бұрын
Theoretically yes, in real life not all materials behave this way. Watch his tire load sensitivity video.
@itaytabib4665
7 жыл бұрын
Yh of course u can benefit from wider tires.. they're also more stable On paper the friction is the same. just throwing it out there
@LeDerpsson
7 жыл бұрын
Thats not completely true. In a tire you have more forces then just the friction between the tire and the road. at first you have cohesion, wich means the tire is going to be deformed by the road on a small scale. Imagine little bits of the road pressing into the tire, thus creating more grip (and even more if your tire is wider). The second force you have to take into account is adhesion, wich are little bonding forces on a atomic level. They are also increased with wieder tires. trust me i'm an engineer
@BrandGSX
7 жыл бұрын
The short and hopefully easier answer to understand is this: Wide tires provide more surface area but also decrease surface pressure equally as you go wider. This would lead people to believe that width has little to no effect on grip but tires are mostly various types of rubber and silicone and also act as an adhesive. This means that while mechanically the grip should be relatively the same you have to account for the adhesion the rubber provides which increases grip as you go wider. Because there is a surface adhesion you now have to overcome the shear strength of the rubber to lose traction. Thats why when you lose traction your tire wears down. Leaving behind small pieces of rubber on the pavement. You didnt lose traction with the pavement, its actually so good that you lost the bond between the top most layer of your tire to the next layer. Remember ladies size matters! Al least on pavement!
@ocping
7 жыл бұрын
Engineer using imperial? Blasphemy!
@PaulDebaecker
7 жыл бұрын
What I learned at school, and on wikipedia, is that friction forces do not depend on contact surface (mathematically it does not, it is not just that the effects are neglectable); besides, for a same material, if you increase the vertical load, you will increase the horizontal force appliable before sliding. So I do not really understand the point of wider tires, from a grip point of view anyway (from a wear point of vieww, maybe it decreases wear...)
@gislemark79
7 жыл бұрын
This video is pointless. USE METRIC!!!
@ZeroneRaven
7 жыл бұрын
Been needing to change tires since you started talking about your S2000 crappy tires, since the car I bought came with winter tires and its getting hot. Finally decided and got a Michelin Pilot Sport 3 in 225 width, 20mm more than what it had 205. Man what a difference in stopping power! It feels like I have twice the grip I had before, love these tires.
@MaverickandStuff
7 жыл бұрын
There is a correlation between tire width and weight. If the tire is too wide for the weight of the car, the vehicle will almost act like it is floating. Also putting a bigger tire on a lighter vehicle can cause you to have a odd tire pressure to maintain correct tire wear. The main thing to look at with tire size is the weight rating of the tires. If you put tires rated for a heavy vehicle on a small car, the car will bounce around. If you put too light weight of a tire on a heavy vehicle, the vehicle will sway and act like it has flat tires.
@alanbrown397
7 жыл бұрын
Back in the 1980s one of the Australian car mags did tests with various widths on the same set of vehicles. What they found was that wider tires give better grip "up to a point", but when they lose grip it's harder to recover it. Tire pressure is also important The stopping distance didn't really change much, but it mattered when cornering.
@TheObsesedAnimeFreaks
6 жыл бұрын
Fogets that break type and breaking friction plays a roll. If you want the best breaking, then you get bigger disk breaks, wider tires, and softer compound on road, and bigger nobs off road.
@kodiak2fitty
7 жыл бұрын
Couple of points to add to what was discussed in the video: - Compound is critical as EE points out. And there is no compound or tread design that is the best at everything. BUT tire technology today is phenomenal compared to even 10 or 20 years ago. - Tire performance can change radically as the tire wears and how it is worn (shagging tires going sideways around a track for example) - Nearly every OEM tire is not the same thing you get from the tire store. In fact, where he pointed out 2 vehicles with the same tire: they are likely not the same. You need to look at construction code on the tire. Most OEM tires are tweaked to exactly the properties they want and can have different compounds or construction techniques. Occasionally, OEMs will take an existing construction code without changing it (i.e. a tire first created for Honda gets re-used on a Toyota). - Car manufacturers generally get the best tires (the most consistent based on specifications). The stuff you buy at the tire store are generally include a lot of the OEM rejects. I'm not sure about the tires if you buy them from a car dealer. - EE got about as accurate as you can given all of the variables floating around. In real tire testing, you have to do A/B/A tests (go back the control tire) so that you can estimate error over the period the testing was conducted. It is very hard to get an absolute performance metric for a tire, but you can see which tire has more/less of your desired attributes.
@N33sWorkshop
7 жыл бұрын
I have Hankook Optimo/Kinergy combination on my Focus and the stopping distance is amazing (in dry and wet conditions), also good grip in corners and good grip on snow.
@vincenitchev5203
6 жыл бұрын
Very good data and information, but another very important factor wasn't really mentioned. That is the vehicle's ABS programming. Some bad ABS program could increase your stopping distance vs a properly programed system. Another noteworthy factor is brake fade, which may seem irrelevant for an initial stop, but some smaller brakes could overheat by the end of the 60-0 stop as well, making them less effective by the end of the emergency stop and increasing stopping distance.
@ChrisCaseboldt
7 жыл бұрын
"This amazing sketch I did truly breathtaking" I literally laughed out loud!
@vacazboara
7 жыл бұрын
Luv'ya for using imperial units. Of course, it is not hard to mentally compute the conversion, but it's still a better experience to have both imperial and metric units on the graphs :) About the video, the topic and the measures: very well done! The common sens is finally backed up by a pretty accurate test :). If you guys live in a moderate/temperate climate you should use summer/winter tires, depending on the season AND the right tire pressure.
@xeno126
6 жыл бұрын
Some people are saying that the test says that there's more to grip than the tyre width. Well, the question remains, if I have a certain car, with certain diameter tyres, I decided on a certain brand and type of tyres, should I get a narrower or a wider tyre? As far as I know both tyres have the same grip ideally, but narrower tyres have more contact pressure and so can deflect more and can dig deeper, and vice versa. So narrower tires are better for digging in shallow mud and snow, and for mechanical keying to a dirt or rock surface. For very soft surfaces like deep mud and snow and soft sand, wider tires are better to keep the car floating and not digging in. But then there's also the geometric aspect.
@tylerpontius8880
6 жыл бұрын
Friction is independent of surface area, purely wider tires do not decrease or increase stopping distance. Widening the tire allows softer and stickier rubber to be used mainly by decreasing the load on the sidewalls. Friction is determined by weight and the coefficient of friction where Friction=Coefficient of friction x Normal Force(usually the weight). You will notice that with this equation the force of friction increases linearly with the weight increase so the coefficient alone will determine the stopping distance for vehicles. The first scientist (Guillaume Amontons) to proclaim this was just about laughed out of the room until one of his peers proved him right. You can test it yourself if you have a force gauge and two building blocks tied together with a string. Do test 1 with both blocks on a table tied together, then do test 2 by stacking the second block on the first and repeat tug test (same weight half the surface area). They will take the same amount of force to move despite having the same weight and different surface areas. What really matters in a tire is what additives and rubber they are made of and how soft they are. Widening the tire reduces the load on the sidewall and decreases the rate of wear, allowing softer/"stickier" tires to be used. There you have it folks the secret to wide tires
@kbolash100
7 жыл бұрын
I have a tire/wheel circumference/diameter question. On C63s AMG, the standard setup is 19in wheels on all 4 tires (255/35 in front, 285/30 in rear) but you can option (for $2,100), 20in wheels in rear and while 19in front tires remain (still 285/30 in rear just with larger diameter 20in wheel). Is there any performance or handling benefit to having the larger circumference wheel/tire setup on the rear tires?
@BowYangJam
7 жыл бұрын
Maybe in road courses, tire width really isn't all that important compared to compound. But let me tell you from a drag racing perspective. I'm worried less about stopping distance and a hell of a lot more about grip on launch. Now, I can run 11.5 in slicks on my car and I hook up pretty damn well. Compared to cars I've built before with 14 in slicks, I can notice a huge difference. More hot sticky rubber over a larger surface helps. Maybe not in road courses but it definitely holds true in drag racing.
@nykerno
7 жыл бұрын
One thing that I have wondered is how much does a thinner front tyre affect effectiveness and stopping distance on a RWD car. For example Tesla P85+, normal tyres 245/45R19 vs thinner 195/55R20. Is the saved rolling resistance greater than lost braking distance?
@dodgethis_9273
7 жыл бұрын
Engineering Explained, I called a local Utah court today and there was a familiar voice on the other line while the intro played. Just found it rather amusing and had to share.
@balthasarlumbantobing4112
7 жыл бұрын
I love how you do engineering measurements just for fun. There are some mistakes on statistical calculation but I did enjoy your presentation. It didn't give me the most accurate data but I think it's a good preliminary study to give general view of this matter. I think it would be a great pleasure for having you as a guest lecturer in Institut Teknologi Bandung (my uni) LOL
@Jackthesmilingblack
6 жыл бұрын
The real issue is grip on snow, particularly up hill on wet snow. Is there more grip with narrower tyres? Glad you called atttention to the USCS/metric mishmash. Don't you think the abbreviation for pounds (weight) should be lb rather than lbs? Consider consistency.
@lliaolsen728
7 жыл бұрын
If load per tire is reduced when you increase surface area due to weight distribution then you need to find the balance between the cars weight and the width of the tire. You can increase tire load by adding a weight or adding aerodynamics to promote down-force which is fine if you are only concerned with braking or turning performance.
@travishooper3036
7 жыл бұрын
Why was this plotted with the independent variable on the Y axis? Independent variable always goes on the X axis and dependent on the Y. Makes following your data points ridiculously hard.
@41ace39
7 жыл бұрын
can you do a vid on how tire/wheels size affect gear ratio? thanks
@MikeHammer1
6 жыл бұрын
The only way to accurately make a correlation between tire width and stopping distance would require using the same vehicle under the same conditions of road surface, temperature and humidity and then vary the tire width on the vehicle using the same brand of tire as the tread pattern and tire compound will otherwise have a huge effect on the results. Even then, the aspect ratio of the tire, tire diameter and rotational inertia will play a role in the result.
@DustinSilva
6 жыл бұрын
Before I even watch; it depends on the surface being driven on and the tire pressure. In snow, mud, etc, more narrow tires have more weight per square inch, which helps increase traction. However, on a normal paved road, the more tire that contacts the road (wider tires) the better the grip will be, assuming the pressure is not too high..
@Glasseh
7 жыл бұрын
How did you like the Volvo V90 Cross Country?
@AIDANPEREIRA
6 жыл бұрын
Heavier vehicles have more momentum and hence will be harder to stop hence larger stoping distance
@im4science77
7 жыл бұрын
When we have to compare something like stopping distance, which has a proportional relation to a number of factors, does the R value of a plot of one of the factors mean anything when all other factors are not kept the same? For eg: If we have to find out whether the wider tires will help in reducing braking distance, tests with two sets of tires on the same car makes more sense right? Normal set and extra wide set of tires on a Mustang will give a more meaningful result than a set of normal tires on a Mustang and extra wide mud tires on a Wrangler.
@Daveinet
6 жыл бұрын
I am concerned that you spread a lot of misleading information. For a test to be scientific, it MUST compare the SAME tire brand and model. Otherwise as proven by your data, your test is completely irrelevant! FACT: Coefficient of friction does not include contact area. This is absolute scientific fact. Do wider tires get better traction? They can but for completely different reasons than most people think. Here is how tires work: Rubber used on most tires today grip the road stronger than their ability to hold together. Try skidding your tires. If you have a soft tread, you leave rubber on the road. If you have a hard rubber tire, it leaves very little rubber on the road. In other words the tire gets better traction than its tear out strength. So, once you reach the threshold of where the rubber begins to tear off, you loose traction. Now, as the contract patch increases, you distribute the load over a greater area of the tire, which means the tire is less prone to tear out, or it takes more force to achieve tear out, as the force is distributed over a larger contact patch. The reality is, that for the tire manufacturer, they need to pick a tire where the tear out strength vs load is maximized for a given tire width. The manufacturers tend tend to error on the side of tire tear out, as it tends to be more forgiving. The rubber stretches as it tears, and tends to not loose grip abruptly. This allows the driver to have some control, even though the tire is sliding. Harder rubber tires tend to loose grip more abruptly, making them more dangerous. In the case of a heavy truck, the weight per square inch is several times what a car tire is. This means the rubber needs to be much stronger and harder, which it dramatically increases stopping distance. It also means when it does break loose, it is very abrupt and uncontrolled. So when you choose a tire, if you pick a softer compound, you should also switch to a wider tire. Simply going to a wider tire, may not increase traction, unless the tire is also softer, or your current tire leaves a lot of rubber on the road when you slide. Most wider tires are more likely to be sportier, and therefore are more likely to have a softer compound. Most people are going to make the right decision, but not really knowing why.
@neilduncan8657
2 жыл бұрын
In michigan we have crappy roads and plenty of snow/slick roads in winter. I use a narrow real snow tire in the winter. My wider all season tires work in the snow but are not that good. Wide tires IMO are only good on dry roads in good condition. Narrow tires are good for bad, rough slick roads These are my observations, I did not make a chart....good video
@shingnosis
5 жыл бұрын
The reason performance cars tend to have such wide tires is to do with heat management and lifespan, not outright grip under optimum conditions. For maximum grip is on asphalt its mostly about picking the softest tire compound possible without overheating, there's much more to it of course but from a layman's pov it will do. On loose surfaces narrow tires are usually better since they will dig deeper and find more grip, but again there are compromises in terms of lifespan, stability and flotation etc.
@impossiblemission4ce
6 жыл бұрын
This seems really interesting Jason! I feel like doing some statistical tests on the dataset myself. Thanks for including your test results in the video!
@BigEightiesNewWave
6 жыл бұрын
I had 315s inside the wheel wells on custom Boyds back in the day on my 88 IROC. Cars were way lighter back then too.
@ulrichseth
7 жыл бұрын
Tire width is only one factor, and it has more effect on the shape of the contact patch than the size of the contact patch. Suppose you have 4000 lb vehicle with 40 psi pressure in the tires. It will have 100 sq in of contact area, or 25 sq in per tire. Supposing said vehicle has 255 section width tires (approx 10 in width) then its contact patch would be approximately 10" wide by 2.5" long. Changing tire pressure or vehicle weight will have the biggest impact on the size of this contact patch. Changing tire width or overall diameter will change the shape of the contact patch more than the size. Tire width will have a much greater impact on lateral grip than on longitudinal grip. Run at the same pressure, a wider tire on the same car is going to have a wider contact patch, but shorter longitudinal dimension to have roughly the same area of contact patch. Similarly, going to a larger overall diameter, all else being equal, will increase the contact patch in the longitudinal dimension, offering more grip for accelerating and braking, though it will also have greater rotational inertia to contend with.
@3v1Bunny
7 жыл бұрын
What would be nice is the disc size extrapolated to this as well. Just to see if the (presumable) standard disc (and caliper) would make for a more significant number. I mean if the wheels are not locking up/skidding (possibly averted due to abs or not) we do not have enough brake power to begin with. Or am i looking at this the wrong way ? Feel free to comment.
@Ghosteriz
7 жыл бұрын
I would like to ask is there any possibility to build a car that the gearbox can either switch between auto -> manual / manual -> auto transmission when the driver seek to during driving, and also able to switches from FWD -> RWD and also 4WD when driver like to?
@mikep2421
7 жыл бұрын
What does tire width have to do with tire load sensitivity? Increasing tire width doesn't increase contact patch area. If it does, it wouldn't do so any more than increasing tire diameter and there was no mention of tire diameter. I would expect tire load sensitivity to be unaffected by tire width, but affected by tire pressure. I would love to see a graph of stopping distance vs tire pressure.
@Espr14
7 жыл бұрын
Can you test dependency of load on stopping distance? They the stopping distance will be longer with more load but I think it is more about tires, ABS and fully stepping on break pedal. Thanks
@andrewthompsonuk1
7 жыл бұрын
Good statisticians hate the use of correlation coefficients in regression. Nor would they attempt to fit lines to data like that. If you removed the outliers the slope may even go the other way. Anyway you ended up with good conclusions. Keep different sets of tires for different uses!
@brunodays
7 жыл бұрын
We need a stock vehicle tested with different tire widths and loads. Now that's a good test.
@kurtblackwell6214
4 жыл бұрын
You should have included tire height in the final table. As you know, braking force at the tire/ground interface is a torque. Taller tires should stop longer, assuming same brake sizing, since the torque of the brakes is divided by a longer torque-arm due to the large tire diameter. To sum up my point, a 255/75/17 tire will take longer to stop than a 255/50/15. Same width, different diameter. I think a cornering test would have been more appropriate to determine if width affects grip.
@jp-um2fr
7 жыл бұрын
A basic fact of friction is that it is not dependent on area. Obviously tread pattern and width has a cogging effect on rough surfaces. One fact that is unfortunately not tested here is aquaplaning which is very much dependent on width. These nice big fat tires might look good but do cause problems in the wet. Bald tires are best and if you don't believe me look at racing or dragster tires - only in the dry though.
@jeffburtonnottheracecardriver
7 жыл бұрын
So, what is the best way to evaluate and rate a tire? How did the P7 do well in dry cornering, yet suck elsewhere - shoulder block design?
@LouisWongPhysics
7 жыл бұрын
+Engineering Explained I think instead of the contact area of the tires, you should consider the pattern of the tyres, and more importantly, the braking force/torque from the brake pad? It is the position where you slow down the car. The tyres undoubtedly affect the friction between itself and the ground, but the friction is only concerned when it comes to slip or not slip (gripping). Even the greater coefficient of friction should not be relevant to the stopping distance. How about do another test on the braking pad (although I have no idea how it can be done)? Very nice video concerning the fundamental issues. I have been very grateful to watch your channel. I was a mechanical engineering student but I learned more from you than my professors.
@jackbrown3958
7 жыл бұрын
Hey Engineering Explained, I actually look at it in a different way. I test my new tires by acceleration from 0 to 60 mph. Although my summer tires (Nitto NT05's) are sticky and much wider than my winter tires, I actually accelerate faster on my winter tires (Bridgestone Blizzak's). I still am not sure which tires I should drag race on at the track during spring & fall. I noticed you didn't include any winter tires on your test hence why I'm wondering why I accelerate faster in the winter on winter tires and wheels and which set to use when. Factors: Summer tires are 275 wide in the front and 315 wide in the rear on a 20 inch diameter wheels Winter tires are 255 wide on a 18 inch diameter wheels (*the circumference is the same as the 20inch wheels/tires due to the "55" aspect ratio) The Winter wheels are lighter than the summer wheels (so less unsprung weight). The DA in the winter is -2000 to -4000 ft where as in the summer the DA is more like 1000 to 3000 ft During winter with winter tires on a dry cold day (0f)I get a very consistent 3.7sec 0-60mph During summer with summer tires on a dry hot day (90f) i get consistent 4.2sec 0-60mph Vehicle: 2009 Jeep SRT8 (modified) ~500WHP/500TQ Why is there such a difference in my 0-60 time, is it DA, unsprung weight, or grip/compound? What tire should I run during spring and fall when the air is cool and the track is colder (lets disregard speed rating of the tires)? Wouldn't the lower DA cause more air resistance? Note: Stopping the distance is always better with my summer tires even in the winter as long as the road is not snowy/icy (brakes easily lock up the winter tires but not the summer tires). Thanks!
@EricFixalot
6 жыл бұрын
It would have been interesting to see how the front to rear weight balance affected the distances. Theoretically, moving weight towards the rear helps with grip on acceleration with rwd vehicles, so I would think moving it forward would help with deceleration. Still a great video, I know it must have taken forever to make and I'm not trying to sound unappreciative.
@roscothefirst4712
7 жыл бұрын
VERY useful, used it to order summer vs "3 season" tires. Have a good set of winters, so switch over for CANADIAN winters (regularly see -40C, which BTW = -40F) Also harder summer compounds (generally) have longer tire life in hot weather than softer all season compounds. I drive a Ford Flex which actually stops quite well as it has massive rotors.
@zazugee
3 жыл бұрын
12:20 this is why dual sport motorcycles have option to disable ABS for trails but motorcyclists are complaing about some companies that make ABS disabling harder for them or automatically come back while they are offroad and cause them to lose traction during technical riding
@jackthatmonkey8994
6 жыл бұрын
There are so many factors that might influence this data I think Every car has ABS and it might be set on different brake forces which might influence stopping distance The ideal test would, intuitively, be a test where the wind is equal for all cars, the amount of aerodynamic drag they generate is known and taken into account, and they all apply the same total brake force for each brake (so front left has "150" (just an examplary number) force on all cars, and rear right "100"on all cars as well) This might give beter empirical evidence. A test where you ramp up the brake force to such a high number where all wheels would lock up might provide better insight as well After that, a test as to how much brake force you can put in the brakes before tires lock up I think that gives the most reliable data because I find this to appear a little too convoluted to really provide a solid answer
@fedzalicious
4 жыл бұрын
Weight distribution, suspension geometry, tire OD and sidewall profile, brake bias and environmental conditions would also have an effect on the results. A single vehicle test would be the only way to gather conclusive data. Still, very interesting results and another great video from EE.
@bararasmus
7 жыл бұрын
Wouldn't it be better to try and compare vehicles of a certain type? If you have a heavy SUV you might have a poor weight distribution during braking while a VW Alltrack most likely has a pretty good weight distribution during braking which should give it a huge advantage.
@MrHeHim
6 жыл бұрын
Contact Patch!!! the width is only part of the equation. Disregarding the type of tire, larger side walls and tire diameter/circumference are the other parts of the equation to calculate contact patch.. After that is addressed then you can more accurately calculate PSI on the tire to the road. What I'm getting to is that you can have 245/45/R16 vs 245/35/18 which have the same width and diameter/circumference but the 245/45/R16 will have a larger contact patch because the side walls are 4.3in vs 3.4in. Same reason you will never see low profile tires on any real track car as it destroys the contact patch.
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