Why Big Wheels Are A Bad Idea On Electric Cars - Range Impact!
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- เผยแพร่เมื่อ 3 พ.ค. 2024
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Do bigger wheels affect EV range? How much more range will a Tesla Model 3 have with 18" wheels, versus 20" wheels? What about a Tesla Model S, or a Tesla Model X? In this video, we'll analyze how tire width, rolling resistance, and wheel size impact an electric car's range. Personally I was surprised how large the impact is! Especially for highway driving, it's important to know how your wheel size can affect your electric car's range. And with the knowledge learned from this video, is it possible that big wheels alone make up a significant portion of our nation's emissions? Join team big sidewall to see ride comfort, cost, efficiency, and emissions benefits!
Related Links:
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I am absolutely delighted that Jason has built several videos from one pothole destroying his odd-sized Tesla wheel.
Gift that keeps on giving!
i was thinking the same..
Somehow he has to get the money back.
Question: shouldn't the comparison be made based on the rolling diameter of the tire rather tha wheel diameter? If the smaller wheel/larger tire diameter combination results in a larger exposed tire area, the some of the gains will be reduced or negated.
😆😆
**CLARIFICATION!** Why do bigger wheels mean worse efficiency, when the overall tire diameter remains the same? This comes down to aerodynamics. A 20" wheel will cause more of a disruption in airflow than an 18" wheel. That's why Tesla (and others) uses aero covers on their wheels (Car & Driver testing showed it gives about a 3% efficiency bonus at speed). The smaller the wheel, the more of the side profile of the wheel & tire is perfectly flat (the tire is flat, the wheel is open: more tire = more flat area, less open area). Ideally, you'd have just a plain, solid sheet for the wheel, but obviously that's not idea for brake cooling. Wheel covers are today's common compromise as they have some airflow, but minimal.
Let's bring back big sidewalls! Watch till the end to learn how fat sidewalls will save the planet. Car community doing their part. 💪😂
Is this applicable to internal combuation cars, I would like to know if I can save the environment too 🤔
Edit: Clarification already did
Can you do a white board video on how much range you would lose by ricing a Tesla? Spoilers, Canards, 45 degree camber ect. 😂
Why does bigger wheels by itself hurt EV range or gas mileage?
I just thought of this. When range testing different size wheels in real life, do people account for the speedometer being slightly off due to the size of the entire tire and wheel?
@@mai_kul If I was range testing a vehicle I would NOT use the speedometer. The range tests are either done with a rolling road or other means of monitoring speed and distance.
It's interesting to me that standard wheel sizes have been increasing over the years from all car manufacturers. It seems like it was just for looks, not for ride quality or efficiency.
On electric and heavy vehicles some of has to do with brake disc size, bigger rims means more room for bigger discs. Another part of it has to do with handling on the limit in heavy vehicles, like when performing evasive maneuvers like the dreaded "moose test" etc. But you are partly right, on some cars it really is just for looks. And many customers would do well NOT to tick those bigger wheel options when ordering a car, I certainly don't.
The size of the vehicles increases too. Also mostly for looks. People drive around in Tundras which are legitimately scarily large with nothing except a handbag with them. They think it looks cool.
The original premise was handling, as in cornering
@aluisious that's part of why Bolt EUV is more popular than EV, a little more back seat, but 6 in longer
Larger tires and wheels also cost more to replace.
Tire and wheel size has increased substantially in the last 30 years. People may not remember this, but cars like the 1990 Honda Accord LX and the 1989 Camry (base version) had 14 inch wheels and used 185/70R 14 tires. As indicated by the 70 aspect ratio, those cars had wide sidewalls and the ride they provided was fine. When I bought a new car in Sept. of 2017, I bought a 2017 Camry LE rather than the 2018 model (which was already being sold) in part to avoid the new dual clutch automatic transmission, but also to get the smallest possible wheel size (16 inches) and the largest aspect ratio (65) I could. Even the higher priced 2017 Camry models forced you to get larger wheel sizes. An article in a car magazine I read several years ago included an interview with an auto executive who was asked why manufacturers kept on using bigger wheels despite the various engineering drawbacks, and he replied that it was largely done for styling reasons.
the main driver, I think, of those "styling reasons" is EU pedestrian impact standards that effectively require a very high hood-line, which in turn causes that "blocky" look with tall fenders, which look silly without big wheels. They're trying to make the wheels proportionate to the chunky look of everything else that the pedestrian impact standards force.
I know this is two years old now but hopefully by now you’ve realized the Camry has a traditional slush box 8 speed auto, not a dual clutch as you stated. Sorry it just triggered my inner autist and I had to comment.
Smaller side shoulder of a tire improves sharp steering in contrast to suspension "ride quality". Today middle driver prefers driveability to comfort. Just a business.
This is true. But also follows that wheel and tyre size *decreased* substantially from 1910 to 1960. Wheels went from 36" on a 1910 car, down to 27" or so on a 1915, down to 21" or so on a 1925 and then down to 18" to 17" to 16" or so in the 1940's and then an even smaller 14" to 15" became the fashion in the late 50's and early 60's, to allow for a lower, sleeker profile of the overall vehicle. These 13" and 14" carried through to 1980's economy cars as you say, but then wheels started to grow bigger again as increasingly low profile radials were developed (starting with radials less than S or standard 82% profile, first coming out in the late 60's).
The exotic 16" "low profile" 205/55 R16 that was once the preserve of a Porsche 911 front tyre in 1985 is now the standard tyre on the most base model Toyota Corolla, and the 225/40 R18 that was so exotic when it was a Ferrari 355 front tyre in 1998 is now the standard tyre on a higher trim level Corolla!
As cars (unfortunately) get taller again more like 1930's cars -- reverting the change to low, sleek, more aerodynamic designs of the 1970's and 1980's -- it makes sense that wheels would get larger again, even if only for stylistic reasons.
To: Tassie Lorenzo: Thanks for your informative comment. I was not aware of the historical information that you provided. @@TassieLorenzo
I remember a race car engineer saying the ideal wheel size is the smallest you can fit around your brakes.
That's why Tyrell ran a 6 wheel F1 car. It worked so it was banned.
Makes sense to me
@@andrewsaint6581 he didn’t run that for wheel size. He ran it because it increased the overall contract patch of his wheels, which gave him more grip.
@@andrewsaint6581 the 6 wheel car had 4 front small wheels to have better grip and better aero on the upper part being flat but has nothing to do with side walls
@Tamara Maschan true, f1 cars try to use small wheels to some extent. I had a similar experience i raced my stock 325 vs a stock 325 but with big wheels and in the 1/4 it did a small difference
This settles it. I'm calling my crush and telling her that 2 inches less is 15% better, I hope that finally gets her to date me.
🤣🤣🤣😂😂
15% increased thrusts per minute, resulting in 15% faster finishing time. Idk man that still sounds like a bad thing for her
jokes on you, i already told her 0 inches is 100% better
Shorter, but thicker.
So you sexually identify as a model 3?
understandably so.
Me: **Looks in bank account**..........**Starts affixing grocery cart wheels to car**
Extremely underrated comment 😂
If TH-cam had a decent algorithm youd be a top comment
I never realized the impact of intentionally going with 16” cheap tire option rather than the 18”. I’m able to get 40.5 mpg average on a 2.0L focus manual. Watching this video really makes me think that tire choice has a much larger impact on mpg than previously thought.
Board: *says 0.6*
EE: "nearly ONE percent!"
That's some healthy rounding right there!
It's Apple style marketing! This video Jason made is the newest video he has ever produced!
More than half at least.
Try it yourself in any program. Even Excel, round(0.6) will give you 1.
"that's nearly 1.7 times the real value" :D
Hence the reason why the Prius always had tiny wheels - 15". Cheap stuff that was good stuff.
The Geo Metro had 13 inch wheels!
And it also makes tires cheap. A set of brand new michelins for my prius was $450 installed
I notice the new MG electric cars have good range and small wheels too.
Great video. When moving between the wheel sizes, the bigger wheels may be heavier. If so would that make a difference? Wondering if a 235 tire in 18 stock wheel is more efficient than 235 tire on a lighter (perhaps forged) 20" wheel.
Hmm, I agree. Same with the early Honda Insights which used a rather small 14" x 5.5" wheel. My 2002 would get between 62 and 64 mpg on the highway everyday but after going with a taller tire I immediately noticed a loss of nearly 5 mpg. Have to stop 2nd guessing Honda engineers.
Hope you read that. I made allot of calculations for my 3.0 Continental in order to understand how tire pressure is determined. - wanted to use non standard 235/50/19 winter tires and keep rolling resistance, contact patch, etc. to spec. Turned out the required pressure is 2.4 bar - the same as the stock pressure of the stock size 235/50/18 - see why below.
245/40/20 - 2.7 bar cold pressure - ~3.7% sidewall deformation
255/45/19 - 2.3 bar cold pressure ~ 3.8% sidewall deformation
Calculation:
1/2 of axle load is divided by pressure, this gives area of contact patch;
Area/width of tire gives length;
1/2 length of contact patch is used to solve right angle triangle as one side, second side - hypothenuse is the non deformed radius and the third side is the effective radius of the loaded tire. Substract r-eff from r-nominal you get amount of deformation in mm. Find percentage from sidewall height and that's your percentage of deformation.
If you play enough, you'll find out that taller tires allow for less deformation especially if they are tall and wide.
For instance, a 2005 Mustang GT on it's stock 235/55/17 would deform them less than 2% at 2.2-2.4 bar cold.
Allot of info can be drawn from this simple calculation.
And btw, your added air drag calculation is not correct. A wheel has Cd of 1, so your 0.03m2 should be included roughly 4.5 times in the drag of a 0.22 Cd automobile thus contributing to allot more drag than you came with.
Best regards!
P.S. you seem to never react to my comments.
Wheel weight also has a lot to do with it (which EE has already made a video about). I had aftermarket 20" wheels (at 35 lbs / wheel) installed on my stealth Model 3 Performance, and my energy usage increased to ~270 wh/m. They looked awesome, but I've been doing a lot of road trips lately and wanted better range. I recently purchased a set of the 19" Tesla sport wheels (at 25 lbs / wheel), and my energy usage is now back to ~240 wh/m - much better :-)
could you link the video on wheel weight you mentioned? Thanks
What is a stealth Model 3 performance?
@@navid8276 It's a Model 3 that has the big performance motors, but the regular brakes, no spoiler, and no track mode. It's basically a Long Range with bigger motors, so stealthily as fast as a Performance model, but none of the change in looks.
they should call it model 3 BIG MOTOR then 😅
The weight of the wheel will have _zero_ impact on steady-state range. The only time you'd notice it is when accelerating that mass up to a certain speed, ergo, "road trips" would be the _last_ place you'd ever notice a mass difference.
Big wheels are pretty much worse all around imo. Without watching the video first, tire are usually more expensive, have worse ride quality, more prone to curb rash and bending a rim on a pot hole. Basically worse in the real world.
Yeah but they look cooler tho.
Well wider tyres give you more grip.
I despise “wagon wheels”. It’s really bad when you put them on a ‘70s/‘80s land yacht and ruin the smooth ride and handling they’re famous for.
yeah, i've been looking at swapping the brakes on my car so i can fit 15s. it's nice to not worry about potholes and curb rash, plus better rotation in corners with the skinnier tires. efficiency is cool too, i guess.
@@SoulTouchMusic93 I don't like the look of the slim tires on huge rims.
Sweet, so my 37" tires on 17" wheels for my truck is really saving the planet. Nice
Assuming those tires are still within the profile of the vehicle. 👍
And it looks right
Lmao sounds like Alberta
Thanks for doing your part! 😂
@@iNick90 ...and weigh as much as the stock tire wheel combo.
As someone that hates 20" wheels on anything, I am glad that math supports smaller wheel sizes.
20's on something like an Escalade look tiny.
This makes me glad I went for the Tesla Model 3 Stealth P3D-!
That is a great reason not to make Escalades.
you can fit bigger brakes. thats about it.
I quite like the factory 20s on my r35
It would be wonderful if someone did an analysis on various OEM and aftermarket wheels and tires to show how they rank for range efficiency. That way, people could compare them and make informed decisions. Using that along with average tread miles on the tire would be wonderful. This is the kind of stuff I wish Consumer Reports would focus their money on.
they just need to reverse the options pricing. "Oh you want the 18 inch wheels? That will be an extra 1000$" "But it comes stock with 20s" "I know. But the 18s will increase your range by 15%".
Of course that argument has no chance against "I'll take the most expensive option please. Spare me the details"
@Peter Evans You are talking about larger diameter tires and what you say is true, but I think the video was about the same overall tire diameter but smaller rims.
So... why does this happen? Why are smaller wheels more efficient? That's what I actually expected you to talk about. The rest of the physics is quite intuitive
Agree. You used Tesla's provided coast down curves, but would love an explanation and the math behind why the curves are different. Is the tire diameter actually slightly different and that is the reason? Or is the weight of the tire/wheel combo different and that accounts for the difference?
@@schmke I think its because larger diameter wheels usually have greater width? I don't know. Yeah, Jason should have explained this!
More of the mass of the wheel + tire is near the outer edge of the wheel. This requires more torque to turn the wheel with more mass further from the center of the wheel. Less efficient
It’s because smaller wheels have less mass and thus less inertia
Smaller wheels have less mass, less mass takes less energy to move
This video couldn't have come at a better time. I was in the process of buying new wheels for my M3P. Great to see some factual information to support my decisions, thanks for the informative video!
Make sidewalls great again!
Make sidewalks great again!
"Lets say you have a very slim tyre, 205"
- cries in 175
Cries in 165 :(
I have 2 sets, the summer set is the "big" 15 inch 185 tires vs the 13 inch 165 ones on my winter set.
I had 155s on my Mirage
BMW i3 - 155/70-19 and they're only made by Bridgestone
145/80-10 Austin Mini . Winner takes all until Chang-Li qualifies as a car
For all cars, you just notice it more on electric.
That's crazy the diameter of the wheel and not tire makes that much difference! You're the man Jason! Keep doing you!
As an ME, I absolutely LOVE your whiteboard work. Such a great channel. Cheers!
Remember when cars had 14" and 15" wheels? Pepperidge Farms remembers.
I remember. I just need to look at my garage, family commuter life
I drive a Hyundai Getz, 14" rim club represent!
My truck has 15" wheels and 32" tyres
My swift has 14inch steelies 😂
I've got a '84 V Jetta Gli coupe with the 14" Snowflake wheels on 175/R14 60 tires, and the ride is rough as it is. I don't want to imagine how rough it would be with 16" or 17" rims with low profiles! Low profiles are the high-heels of the automotive world: looks great, but impractical.
Well, Forza models this well since increasing rim size lowers the car's stats slightly
Not trying to kill the joke but, that's because of rim size, the bigger the rim, the heavier.
but in forza world, burn outs happen with rev hangs 🤣🤣
Happy to finally see you cover this topic thanks Jason!
Given the popularity of SUVs/Crossovers, especially those with larger wheel base intended for off-roading, I'd be curious to see your analysis of off-road tire efficiency.
Oh yeah!!! I love this video, Never got to liking Low-profile wheels. Yes they react faster but then again, more expensive, louder, stiffer and doesn't protect rim.
And you can't run white walls.
Yeah that’s why I loved the 18” wheels in my 2008 Bullitt Mustang. Nice fat sidewall. Looked nice, rode nice and protected the wheel better.
There is more to it than that, a wider tire on the front will give you worse turn in. There is a fine balance and a few other things he doesn't cover in this video that are a major part of efficiency and performance.
I would like to know the impact narrower tires have on braking distance.
All aspects of performance. Braking, acceleration, handling. How big a tradeoff are we willing to make for range vs performance?
And also the performance changes that would come with larger sidewalls
It has very little effect. Grip isn't changed much, as for any given tire pressure the contact area is the same regardless of tire width.
@@jonboy602 how can contact area be the same regardless of width? The wider the tire, the more contact area, no? I get that aspect ratio beyond a certain point isn't going to take away from performance. What is the best for each of these cars for performance, safety, and economy? It depends.
@@jonboy602 that is very much not true. Contact patch is roughly circular, small changes in the radius of the contact patch result in large changes in area.
From my own anecdotal experiences, I replaced 205/75/15 tires with 255/60/15 tires on a RWD car. With the 205s I was very easily able to break the back tires loose and do a burnout on dry, clean pavement. With the 255/60/15 tires it was not easy to break the back tires loose, I simply had grip. Admittedly these were not the same brand of tires, but they were targeted towards the same mid-priced market.
7:50 Changing tires at 75mph. You, sir, have one hell of a talented pit crew.
Recently switched from 18 to 19" wheels on my Model 3 and I thought I was going crazy or my battery was just degrading after my range went almost exactly from 299 to 284 and I noticed higher wh/mi when driving so this video provides great clarity and closure haha.
Did you change back to 18" wheels? I'm thinking of going from 19" to 18"
6 inches of groudn clearance? *laughs in honda Fit
groudn
Right. I'm constantly scraping mine on my driveway
110 mm is about as low as it gets on any car with stock suspension that's on the road, and that would be a first gen bmw z4, but a Honda fit at 130mm is still far lower than a porsche 911.
My yaris is basically slammed from old suspension when there are more than 2 people in the car. Scrape city is not a fun place to be
After driving a Hyundai Accent, it makes me want my next purchase to be a jeep
In Swizterland, we have a lot of those BMW i3 cars. I meet some everytime I go out. I'm always impressed how narrow their tires are when you compair it to 90% of the rest of the market. This is at least one thing that BMW made right on this car.
Base i3 wheels are 155/70R19. Definitely narrow, but also much larger outer diameter than usual. Really unusual setup.
They look really cool if you ask me. Reminds me of old Beetle-wheels :)
bmw could have given a smaller wheels with wider tyres and still got the same aerodynamics benefits..
@@superchargedpetrolhead I don't believe it no. The wideness of the tire is the thing the wind sees when it hits frontal under the car. It can be channeled to some extent. But there is always some air that will frontal attack the wheel base.
You can look at eco-protoype racing. The tires are nearly roadbike like.
On my 3P I have gotten custom made 19x9.5 wheels weighining about 4kg less than OEM 20" per corner.
Then it rolls on same type of tires,so much less rotational mass, much less unsprung mass. Better accelleration, better braking, better handling (less work for suspension).
Then also the car is dropped quite a lot on KW V3 coilovers.
Your theoretical presentation is very impressive. Last year I went from a 19 to 20" wheel on my Model 3 Performance. My daily commute is approximately 100 miles round trip. For the time being I get to enjoy carpool lane access in my state driving solo, so I'm able to cruise at about 75 mph. I've noticed only a 3% real world increase in battery usage.
What’s the point to increase tires then?
Thank you for the great explanation :D
Hope you are doing well in these weird times ;)
Greetings from Norway
Yay for Norway. Big time EV leader.
I would like to know what effects driver weight might have on range. To keep math simple while using weights within the reasonably expected range at your local Walmart, you could use a 160lb individual versus a 320 lb individual.
most people who shop at walmart aren't going to be driving a tesla
lol
@@Blox117, that's like saying most people who shop at Best Buy aren't going to have three nipples. Most people aren't going to be driving a tesla, regardless of where they shop.
@@Blox117
Where else would you go?
@@---cr8nw well it was mostly a joke about economic status and wealth, not statistics
@@Blox117, well.... joking about people's economic status and wealth.... classy.... You seem like a person I wouldn't want to know.
I have a Lexus Fsport IS350, I just bought 17's for my winter set (vs. the 18's on the summer/spring/fall set) the combination of taller sidewall, narrower section width (225 vs 255), and different tire compound completely change the handling characteristics, and as a result, my confidence in it's handling in the winter. I expect they will get better as the temperature drops, and I'll be experimenting with tire pressures, but I can't wait until spring comes when I can get my wider set back on.
Just something worth considering when having a wheel & tire discussion.
Last week I swaped the summer for the winter wheels. 19×10 285 45 R19 summer to 235 65 R17 winter. The consumption dropped down about a liter on 100km. Range went from 950km to 1150km. For people who like units in a stone×leg per evening style, that's a difference of 4 miles per gallon and about 120 miles more range! On a X5 Diesel.
I have the best Tires. My wheels go around, like no other ones do.
Many people say this about them. Great tires.
Really interesting data charts. The impact vs speed relationship seems to vary depending on car, with the model 3 having a much bigger (30%) difference at low speeds while the others having less difference at low speed. Seems to imply that something other than aero is strongly impacting the model 3 numbers.
electric motor impedance
Love the analysis! Thank you! In the rolling resistance analysis, I was thinking that the angular momentum of greater radius wheels would contribute as well..but as per your clarification below, since overall tire radius is the same, it's instead just taken into account in the graph curves that Tesla submits...?
Glad to see an analysis showing a positive environmental advantage of going for sensible over popular choices. Thx!
On the upside, you don't have to worry about your wheels getting damaged by potholes since they're smaller sizes
"your"
you are wheels
I wouldn't be so sure of that
I ruined a 16inch alloy rim and its tire on a pothole and was only doing about 25 or 30. Wasn't even a monster hole
Is that because smaller wheels don’t go as far into the pothole as big wheels?
I read a guy put 15 inch show tires on his Bolt and gained about 20 miles of range. The snow tires were not even low rolling resistance, where the original tires were. I think they come with 17's.
You should make a video about what tire pressure to use. Lots of people believe that you gotta run the max psi the tire says for some reason. And mechanic shops do the same when installing tires. When I bought my truck new they set it to 40 psi . And it was supposed to be at 29.
I've been watching your videos for years. I love the fact that you save me having to do the calculations etc on my own, as this is not easily available information. And based on this video I have decided not to put the larger wheels I had before buying my mg 4 on the car.
It would be interesting to see the difference in range between an aerodynamic wheel that is heavy (most likely cast) and a lighter wheel (flow-formed or forged) that is not aerodynamic in the same size and a + size. For example, a 16'' e-Golf wheel (aerodynamic, but very heavy) and let's say an Enkei RPF1 (not aerodynamic, but light).
Wheel weight is irrelevant in steady-state driving, it would have zero impact on range (OK, maybe a minuscule amount due to the curb weight being a tiny fraction higher...)
Interesting video and nicely explained. One thing that would be interesting though is the difference of weights for larger wheels vs size.
For example would a 19" wheel that's 1kg lighter than an 18" have much affect on range? I know it's more acceleration but over the time of a full battery surely it's of some significance that could maybe allow going bigger and have less of an impact in range?
It's all about aerodynamics, it has almost nothing to do with weight. A slightly lighter/heavier wheel would change the inertia to overcome while accelerating, but do nothing steady-state.
I really liked this summary. It was well presented and easy to grasp. One thing I thought was missing is tire radius. There it is the other way round: larger radius gooder! (poor grammar intended)
A prime example for this is the BMW i3 and the reason behind this, as far as I understand, is minimising the tire dampening losses as the tire gets deformed in the contact patch. Larger radius means less curvature means less deformation necessary to form a contact patch of given size.
Thank you. Very well explained. I do see about 10% loss in range with the 20’ wheels & tires. 🤦🏻♂️
This is an extra reason. I want to get away from low profile because I drive on typical city roads a lot!
Bigger (& wider) wheels will very likely increase the stress on the suspension components and the wheel bearings. I kept the same size on my car but searched for lighter wheels to reduce the unsprung weight. Excellent video!!!!
Typically, the wheels are not wider and the tire width is the same. As long as the offset is is the same, even a wider wheel would have no impact on suspension "stress". It's strictly a "+1" or "+2" aspect ratio change for looks alone, nothing else.
I always watch these videos to the end. Most of it goes over my head but I'm comforted by the idea that if I really needed to figure something out, there's a formula for it. Great video. Save the planet with tires.😎
Quite an amazing timing. Just changed my tyres from 185/65 14 to 245/40 17. Very helpful video.
Tesla's range graph is based on their OEM 18"-21" wheels which also have increasing weights as diameter increases. So the drop in range can be due to increased unsprung weight and not necessarily increases diameter. So if that is the case one can install larger aftermarket wheels (forged or flow formed) that are lighter than the smaller OEM wheel, and possibly achieve the same if not better range.
+1
Wheel weight is irrelevant in steady-state driving, it would have zero impact on range (OK, maybe a minuscule amount due to the curb weight being a tiny fraction higher...) As Jason said in the comments, it's 100% aerodynamics (poorer) of larger wheels of a similar design.
Nice vid as always buuuut: I'd like to know the reason why there is a difference between different diameters. i.e. the reason of the graph at 7:44.
I saw your clarification but i can't understand. If it is only a matter of aero, why the gap in efficency gets smaller increasing the speed? (9:20)
I mean, and please correct me if i am wrong, the higher the speeds (linear or angular) the more relevant the aero. What am i missing?
And, why data from Model 3 are so different from X and S? X and S numbers are not weird to me but damn, i can't conciliate with thoose of the Model 3 xD
It's not the actual diameter of the wheel, it's many factors associated with that diameter. A performance tire has more grip, therefore more rolling resistance. The SAME wheel in a larger diameter weighs more and is more rotational mass. If the larger wheel comes with a wider tire, more rolling resistance again.
In other words, the combination of the wheel and tire are the true factor, not just the diameter of the wheel. I can assure you that you can find some taller wheel combinations that will yield better fuel mileage if the wheel is lighter in weight, skinnier, and you mounted a Low Rolling Resistance style tire on it.
However, in *general*, the larger the wheel diameter, the more likely to have a performance tire (sticky) and the more weight and more rolling resistance.
It must be predominantly the total weight. If you look at the tables, the biggest effect is on the smallest (lightest) car at the slowest speeds.
Dude , I love you ! You are answering all my questions about my M3P coming soon . lol
I noticed this dramatically on my E92 335i. It came with 19" wheels with the sport package. I put 18" forged wheels on. It was noticeably quicker off the line, turn in was quicker and bumps were less jarring. Not to mention replacements are cheaper on smaller diameter wheels and tires.
Would a 17 inch wheel increase range? Great video and as always, great information.
They would presumably, yes, as compared to a larger size. I don't think you can run anything smaller than the 18" wheels on the Tesla though due to the giant brakes. Anything smaller would not have clearance. Theoretically you could fit smaller brakes but that would be seriously compromising driver safety trying to chase energy efficiency which is not advisable.
I'm guessing 17 inch wheel wouldn't be possible to put on Tesla Model 3 Performance because of the brake disc size.
0 inch wheel = maximum efficiency
@@Blox117 limf(x) as x->0^+ = infinity.
@@4R8YnTH3CH33F Custom rotors built on the axle instead of each wheel would solve that issue. Upgrade by using greater # of pistons in calipers.
*BRING BACK 14" WHEELS...* and white walls too, why not?
My 1st gen insight has 13 or 14" wheels. I got "only" 65 mpg the other day without really using the hybrid drive.. because I had low tire pressure.
White/yellow lettering is making a comeback already. I want to see more of it!!
Cadillac had something interesting going with the last gen CTS. You could get rims down to 17” but they scaled the sidewall down a touch and didn’t make the fender wells huge so it looks damn clean.
15s and some sidewall are perfect
I had a car with 12-in rims. Talk about hard to find tires for it.
Sums it up perfectly. “Bring back big sidewalls and get rid of silly low profile tyres!” Win, win, win win!
I do not understand the absolute obsession that many people have with ultra low profile tyres.
They waste less rubber
It would have been interesting to know if this also effects cars with internal combustion engines to the same extent. I would like to suggest you doing a video on the placement of brake calipers and why they differ between front and back wheels and from one car model to another. Thanks.
it affects it the same way, just because of the inefficiency you don't notice as much. The energy requirement is the same, and you will notice higher consumption with wide and sticky tyres. It's just that let's say, a difference of 10kWh in wind an rolling resistance is about 1L of fuel per 100km. And as he's shown, this difference is very speed dependent so you might not actually see any difference in your use case. He calculated everything at 75mph average so yeah, to have a 75mph average over long distances, without braking, hills, curves, overtaking...is pretty hard. That's why you shouldn't take these results at face value because in your use case it may have a much bigger or much lesser impact.
Brake calipers are placed best to balance the car's weight. If your car has 50-50 weight distribution chances are you're going to see the front calipers towards the rear (at 9 o'clock on the disc) of the car and the rear calipers towards the front (at 3 o'clock on the disc). Else they influence the forces of the unsprung weight of the car, how these dynamic forces act on the steering and suspension.
11:07 hahah bigger wheels on a tesla, make sure to ask why do you hate the environment lol
Tire shaming! Lol
What about the unsprung weight added from bigger wheels, how does it affect performance and range ?
It doesn't. It affects ride comfort and grip over bumps, but not range.
It will affect range in stop and go traffic. It takes more energy to accelerate with more weight.
Interesting to know that weight won’t impact the range? Can you explain
Hey Jason! What 18” wheels did you go with that clear the performance brakes? I’m looking to drop down my wheel size also! Thank you and always love watching your videos! I’ve owned about 4 cars that you’ve owned and now I’m with you again on the Tesla!
the quality of these videos is amazing. Exactly what I was searching for (and the maths still works after 2 years, oddly)
What about if you keep the same wheel size, but switch to a tire with slightly taller sidewalls, such as going from 225/40R19 to 225/45R19 with the exact same wheels?
Would this approximately 4% increase in circumference also equate to better efficiency, or will the added weight of each tire negate it or even decrease efficiency?
Your tires may rub against the wheel wells during sharp turns.
BMW I3 owners have just entered the conversation...did someone say pizza cutters? Lol
Alot of them were changing their 20s that come on the higher end model to the 19s because the ride was so harsh.
What I was hoping to learn from you was the difference in 1) mass of a large wheel with low profile tire vs. small wheel with high profile tire; and 2) the angular momentum difference in the two.
Total mass , wheel + tire
@@rp9674 That didn't explain anything.
Interesting vid! At first it was hard to believe adding 2" to the diameter would make much of a difference, but I got to thinking about my work with wind generators many years ago. Most of the power is made from the ends of the propeller. Power increases by the ^2 of diameter, and power is increased ^3 (cubed) of velocity. So, think of all this in reverse. The tips of the wheel spokes are traveling much faster with increased diameter. The wind load = speed ^3. Another interesting observation is that the wheels used on cars setting speed records on the salt flats have solid wheels.
If you lowered the tesla with 18in rims would you gain mileage?
Did you even watch the whole video mate?
The answer you were looking for is - yes.
Best to go donk with your tesla, go big or go home
@@jeeewhyyypheee yes but he didn't go into lowering the vehicle, he stated the ride height was 6in off the ground
@@defnub he talked about aerodynamic front area of the tyres, lowering would reduce this but gains will be very small. less air underneath is also less drag.
When coparing the 18", 19", and 20" on a VW ID.3,
Bjørn Nyland didn't really notice too much difference, may be like 3% total?
For a 500 km range that's 15 km difference. That's quite a lot actually.
On its own it might not look that much...but % tend to aggregate.
Say you have a big tire...and you're using the AC also 'cause it's hot...maybe a bit of traffic also (happens often in California)
All of the sudden you're losing about 15% efficiency (3% from the bigger wheels, 5% from the AC...7% because of traffic)...now you just lost *75 km* of range !! Those 15 kms from the wheel would come in handy....
I suspect VW is using similarly low rolling resistance tires and aerodynamic wheels for all three sizes, hence the smaller penalty for larger wheels. I think this is more representative of the true impact of larger wheels.
Tell me you're going to teach engineering? You're an outstanding teacher.
looking at upgrading my mach e wheels, thanks for the help
We use to think: I would pay more and get bigger tires because they look cooler, now we think: I’m gonna get the bigger tires “to show people that I don’t have range engziety” lol
Anxiety*
@@kamikazi2500 yep- that. Lol
How does the mass of the wheel and moment of inertia contribute to amount of range loss vs merely a size increase? Could it be more due to this?
Very unlikely. The energy to accelerate the wheel is far less than energy to accelerate the whole car. It's negligible. Also, are bigger wheel systems actually heavier than smaller wheel systems?
@@mitchellsteindler Simple math for me, smaller diameter take less energy to rotate. Thus can make greater total distance required. But downside for slower top speed compared to bigger diameter
@@mitchellsteindler It depends on the tire. Aluminium rims with thin profile tires might not weigh a lot, but put a smaller size rim and a very thick tire... it will definitely up the weight.
The torque ratio has more effect.
Inertia is M*R^2. Here, mass difference would not make much difference as compared to the diameter.
Fascinating. I did not expect that and look forward to revisiting this topic when the cybertruck data is available.
Don't own an electric car, but need to get new set of tires for my full size pickup. Thanks to this video, I now know what to do about wheel size and tire profile. Thanks!
"You can ask them: Why do you hate the environment?" :D
I can't hear you over how cool my 25" wheels look.
do they, though?
@@Turk380 he prolly has one of those jeeps that is garage queened
@@Turk380 He can't hear you over how cool he *thinks* his 25" wheels look.
@@TristanJCumpole this guy gets it
@@BirdiesGoCherp Obviously I am the only one....
Thank you for being the one person on youtube who understands car and tire physics!
I appreciate this video! I have a M3 Performance and I'm looking to get new wheels/tires. Definitely going to step down size to help improve efficiency but also for more a comfy ride. I plan as well to lower the car with TEIN coilovers. The wheels I'm looking at right now are Titan7 19" and the New Aero Wheels 19". I am wondering which one will get me better efficiency. Thoughts?
Wouldn’t the larger sidewall of the higher profile tire increase rolling resistance because it allows the tire to flex more?
More than made up by the weight saving from the smaller wheels. Jason's last video on wheel sizes showed shocking differences in weight.
@@srinitaaigaura depends on the wheel and the material its made out of, if you're going for performance, those wheels will be significantly lighter.
I thought it was more about the "Weight" and the (Rotational Mass)
Exactly, he didn’t mention the weight at all.
Weight of the wheel only affects energy required to accelerate the car. When driving at a constant speed, wheel weight doesn't matter.
@Art Uro That's because a fat, low-pressure tire has a lot of rolling resistance while a narrow high-pressure tire has very little rolling resistance. It doesn't have anything to do with mass. The mass of a wheel only affects the energy required when accelerating. And electric cars have regenerative braking, so even if the tire has more mass, then you get more energy back when decelerating.
Unsprung weight should make a difference and none of it is covered here.
Really enjoyable, thanks for the hard work
great video! I hope you taking the reduction in wheel speed with bigger dia and thus air friction loss into account ?
I wonder how the weight of the wheel factors in to all of this. Does the weight of the wheel make a difference at a constant velocity or does that only effect the amount of energy it takes to change the rate of speed of the wheel? So if you upgraded to a bigger wheel that is lighter than the smaller wheel, is that enough to off set the aerodynamic losses with all other factors equal? 🤔 Sounds like some experimenting is in order.
Great video👍
The weight of anything is almost a non-issue at constant speed.
At what point does going smaller no longer improve range?
Practically, when the wheels no longer fit over the brakes and rotors.
When the friction of the car sliding on the ground equals the reduction in rolling resistance.
Thanks for the very good explanation. And the 13" x 5 1/2" wheels on my '72 bmw 2002 ride and handle beautifully. 🎉
People ask me about this EXACT thing all the time. Why do cars have big wheels now adays and what are the benefits? I tell them, each time, handling and steering response, everything else is a loss. Loss of HP, loss of gas mileage, worse comfortable ride, loss of money for higher cost of tires and the damage is more likely/often from potholes and curbs, more expensive wheels to replace, efficiency, etc etc. Of course, most people think larger wheels look better also... but that's just a trend that manufacturers have gotten into, which they could all back down on.
As I tell them, it all comes down to balance. How much better handling and steering response do you want while sacrificing everything else. Each time, they state they'd prefer smaller wheels, as they don't even push their cars that hard. Now if all manufacturers could back down on the size, we'd be a happy planet. I don't prefer large wheels, stock size is good, smaller is even better. The limit being the size of the brakes and what can you fit over them. Usually, u can go down 1" or 2", sometimes 3", depending on the car. About 20years ago, cars had smaller than optimal, now we are waay larger than optimal, in my opinion. About 10-15years ago, wheels were the correct size, no need to go up or down.
So go buy a used 10-15year old reliable car (Toyota, Mazda, Honda, Subaru), and call it a day. That's what I call efficient, and no electric car costing 4-10 times more can compete. Better yet, get an 10-15year old Hybrid/electric... but I can't stand those things, too slow, too boring.
00:51 whiteboard! 🤣
So fat tires and small wheels? Sounds like a perfect drag setup to me...
You know it.
great videos man, you helped me choose the same car and wheel package, is there a reason other than cosmetics you chose the 18 inch TSPORTLINE wheel you have (aero advantages)?
What should decide wheel size? Brakes! The brakes need to be large enough for the performance of the vehicle and that alone should decide the wheel diameter.
That was a VERY weird and unusual episode... 🤔
When looking at engineering explained, you typically can sit down and relax, being pretty sure that the perspective is going to be scientific. But here you are analysing the impacts of physical things, but when it comes to wheel diameter, you just basically say “Tesla says”! 😳
I’m not saying that Tesla is wrong, and I don’t hate high sidewalls, on the contrary - I love high sidewalls! (Yes, I am that old.) I like the tire to be/remain the mechanical vibration isolation that the tires were invented to be! And I like formula one cars to use wheels with high sidewall-tires!
So I’m really sad about the new F1-regulation change, applauded of coarse by the tire manufacturers that have been pushing the meme “big wheels/low tires is better/cooler/sportier” for so many years. 😕
But - you just can not just buy the numbers regarding range, directly from Tesla!
Other people play it like that, but not you! That is not scientific!
The range depends on so many things! Tire pressure for one. It just is so unscientific to talk about diameter of the rim so people with less knowledge mistakes it as something that’s proportional to the circumference of the wheel with a tire on.
So please be your normal self and go into the physics! Don’t just quote claims from Tesla!
If Tesla’s right regarding the range being almost inversely proportional to the rim diameter (even when to tires outer diameter is unchanged) then go into the WHY. Tell us about sidewall losses that becomes higher when the sidewall is exposed to a higher degree of relative deformation.
Or just ignore me. 😀 I am sometimes unnecessarily negative. ☺️
I'm pretty sure he used that data because a) it's available online b) it's very likely measured data c) it's pretty much impossible to calculate that stuff by yourself. You'd need to run very advanced CFD simulations on a very accurately 3D modeled car to get the drag data. Then you'd need to do some sort of physics simulations on how different tire sidewall heights affect range. It would probably take weeks of full-time work and very expensive software and hardware to be able to calculate this stuff. So why not use data that is already out there? I don't know about the USA, but at least in my country, false advertising is illegal. So if Tesla is advertising those range numbers on different wheel sizes, I'm pretty sure they aren't lying. And the most important piece of data there isn't the range itself, but the difference in range between different wheel sizes.
Would've been interesting to also look at total wheel and tire package weight differences. Usually smaller wheels are significantly lighter, if I'm not mistaken.
The tyre would be significant more heavy assuming that the total circumference must be nearly the same.
Depending on material use for the wheel and which has more effect...extra weight of rubber against less weight of the metal.
1:39 There is a missing component : (4) the effect of a wheel cover on the Tesla Model 3 with 18" compared to the 18" / 19"/ 20" with no cover
Very informative. I have an 18 inch on my 22 m3. Nice to know I made the right choice