Bigger wheels put a slightly bigger load on the motor, but if the motor was that finnicky about load, why only a single speed transmission? For the same speed, the motor will turn slightly less rpm, but will it draw more current in steady state? Likewise with super tiny wheels, you might get to where the motor rpm actually gives you slightly more mechanical losses, although electric motors without regen engaged generally free-wheel a lot better than an internal combustion engine, making higher than optimal rpm preferrable. You might find you release the accelerator slightly, reducing the current again, but the load doesn't seem that extreme. Not like trying to motorise a penny farthing with a standard electric bike hub motor designed to output 250 watts at 200 rpm, that will be operating overloaded most of the time.

all benefits aside, it even looks better to go with more rubber and dark 18 alloy wheels...

CO2 is the GAS OF LIFE - the planet does not need "saving" from it.
Efficiency, yes, woke zealotry no thanks.
Planet needs saving from woke zealots and I don't mean this presenter ...

What about handling? I guess smaller wheels have less grip on curves.

looking at upgrading my mach e wheels, thanks for the help

So this video doesn't take into rim aerodynamics or that large sidewalls can negatively handling due to sidewall flex. which is actually worse when you have the lip of the tire hang over the rim more. This protects curb rash but does help performance. What was your actual range and consumed power on the smaller rims vs larger rims?

I’m starting to wonder why the Model Y didn’t have an 18” wheel option. It seems like it would improve the ride, and increase the range a bit.

A total waste of time

Not nearly 1%, nearly 0.5%

Did I miss the reason why wheel size has this impact? Is it rolling resistance?

I totally agree, this big wheel thing is ridiculous, even full on race cars,stock cars, formula 1 they all have more sidewall then your average sedan.

aren't bigger wheels make bad quality road feel smoother? small potholes on large wheels make smaller impacts

Shorter sidewalls usually translate to better handling. I switched to shorter sidewalls and it made a noticeable difference at higher speeds and cornering.

Good video! But I still don’t know whether rim diameter alone with all else equal (only the proportion between rim and tire wall) has any noticeable impact!

still doesnt really explain why larger diameter wheel leads to lower efficiency

How close does this apply to an ICE driven vehicle?

He doesn't explain why the smaller size changes efficiency so much. Why?

According to my calculator from a dolar store the diff is not 0.015 but 0.15

My 17" wheels with 37" tires don't get great mileage......

good dialogue

This is the best channel on Youtube.

But a low profile tire, or side wall does neccessary mean a bigger diameter wheel, this is just what Tesla offers. Also a gearing change can equalize the wheel diameter change, so we can still save the planet with cool wheels ✌🌏

Intuitively I thought bigger tires were more efficient since they move the car more per rotation.

Where did you get your wheels from?

I wish I knew this before I chose the 21's on my Model S.. but damn they look so good

There is a mistake:
Bigger tyre with = big impact on aero CD number!!!
Wheels are like parachutes for the aero!!!

Is it possible to Model S Plaid to reach 100 kph in 2s ¿?
In one video you posted, you said the fastest 0-60 was in 2.05s ¿?
Thanks

Potholes are number one reason.

Would love to see how wheel and tire weight affects mpg

hello @(Engineering Explained), could you post the A, B and C coefficients of your curve-fitted function? Because the math model do account only the rolling friction which is (F is proportional to V) and the aerodynamic drag (F is proportional to V^2), but because we use only a simple model my interest are how much impact have the second term (B * V) in your equation compared to (A) and (C * V^2)

Awesome video!

Tell me you're going to teach engineering? You're an outstanding teacher.

Given total diameter of wheel/tire combo, tire width, and and same actual tire compound and tread pattern, other than a larger wheel possibly being heavier and possibly causing more air resistance (which is not necessarily so), there should be very little difference in efficiency.

Isn’t the rolling resistance mostly from hysteresis in the tire rubber rather than friction coefficient on the road?

Honestly, most public roads are not maintained well enough for 20+ inch wheels to be a good choice. It makes the ride quality worse and much more likely to get a flat tire or bent rim. Performance and aesthetic gains from large diameter wheels is not worth the other drawbacks.

I don't think you actually said why bigger wheels are less efficient. If the overall tyre diameter is the same why does it matter if you have bigger or smaller wheels? Is it just a weight thing?

I am in the same boat with my P3D - and this math checks out approximately.

The car industrie has got reason - it sets trends, trains people state of the art (design, technologie, financing, legislation, etc), keeps people busy and occupied, contributes to a nations gdp, thus provides force that can be directed (inside/outside) - it has nothing to do with transportation or environment. At least not very much.

Seems like he's basing this on rim size and not total tire height? Shouldn't this be based on total tire height?

Your brain cells must be in steroids! You should be working for NASA. All well said, unfortunately, some people simply go for the looks.

Big wheels increase unsprung weight, affects handling, braking, and acceleration. Plus it burns extra gas and electricity

Stick with 18 inch. They are lighter and you have more rubber to absorb ruts and curb bruising. I owned a MB S class with 21 inch rims. It destroyed the handling with increased unsprung weight. I hit a large pot whole, blew all four tires and cracked all the rims. Went back to 18 inch

So 11 minutes of basically explaining that more rotating mass = less efficiency... pretty much could summed that up in 1 minute

SLOW DOWN ! Do you have a 'plane to catch? No! Then speak normally.

But, why? Why does a larger wheel reduce range? The diameter of the tire is the same, width is the same. You didn't explain that. Engineering NOT explained. ;-)

I thought the range would be improved with the larger tyres diameter as it increases the gearing. ie for every revolution it goes a bit farther than with the smaller tyre.

I'm impressed. You are talking to me as if I was intelligent enough to understand it.

Just watched this video. Thanks for the explanation. Question and clarification on wheel size. Do the larger wheel sizes refer to the diameter only or do they also include wheel width. If only diameter does the resistant force increase with speed because of the wheel mass difference and slightly increased frontal area of tire ( assuming width is the same from 18-20” rim). Please clarify why larger wheel dia increases resistance force

how about tyre pofile 45/50/55/60% efect rolling resistance?

Tesla is cute with their EPA numbers. Subtract 100 miles from that 75 mph range for the real values (Car and Driver testing vs Taycan Turbo which matched EPA range).

What if you use a hubcap over the wheels. That will improve aero, right?

I like the look of bigger wheels or smaller tires

Is the difference in range from wheel size just due to increased weight? Often switching from factory wheels to aftermarket wheels will drop the weight if you do it right. What happens if you go with some super expensive carbon fiber wheels for example? Or even better, the smallest size carbon fiber wheel.

2in difference definitely does give a big impact.

This is about wide tires, not tall tires ? ( All tires matter.)

No car needs less than 50 PROFILE tires

They say that electric cars are good for environment. But where do dead batteries go?

Driving around in town with 30 mph, the difference can even be 25%! That is substantial...

Ok but why ? It is finally Tesla data that gives the 15%
Is it the aerodynamics of the side walls ? (mainly inner side wall) or the shape of the rims ? Or what ?

As an OEM engineer, I was really disappointed there was no explanation of the rationale behind this theory.
I read the update below, that is was an Aero benefit. If that’s the case, you should be promoting smooth flat wheel surfaces not smaller wheels because the wheel size is not the real reason.

@ 1:55 " air rushing beneath the car"
The air does NOT rush beneath the car.
The air is pretty much standing still.
Engineering Explained.
Thanks for that insight, Jason.

Work = Force x Distance = change in energy.

Yeah but saving $ is not COOL. JK

I still don't understand why a change in wheel (rim) diameter alone would impact range so much. It seems to me that tire profile/width difference between wheel options explains most of the difference in the Tesla case ? I was hoping to understand how a bigger tire wall leads to better efficiency. E.g. is there less energy lost in deforming a bigger tire wall as opposed to a smaller tire wall ?

how are you calculating the range vs speed chart? I'm curious to develop one for my car and to see what the factors might be going from an 18" wheel to a 15 or 16" wheel.

EV fan boy

It’s not only how to save the planet, but also how to save your wallet against unexpected expenses, due to the fact that we don’t live in a perfect word. A tire with a taller side wall will give softer ride. Because they double as an air spring specially protecting us against unexpected pot holes that our “drunken insolvent state governments” can’t properly repair and only do band-aid fixes again and again. Low profile tire make Tesla efficacy rating look good that good for marketing. Further, this is not efficient in your wallet when you come across an un detected pot hole that make a hole on your wallet and gets you in to deeper debt since you had to resort to your credit cards to bail your self out. Jason dose this sound familiar...Hummm....
Less impact on the environment but more impact on you hard earned fiat (monopoly money) dollars.

*laughs in liking small wheels*

Just put F1-style wheel covers on the wheels and you're done - no aerodynamic impact, all the range.

10:45 the moment it felt like TV shop with a white board :D

Why does no one mention that a 20" wheel travels farther in one revolution than an 18" wheel?
Seems to me that you would record a higher travel range on a lower wheel size than a larger wheel size though they travel the same distance. This is because a smaller wheel will have to make more revolutions per distance than a larger wheel. The odometer would have to be re-calibrated for the different wheel size changes to give accurate travel results.

I'm sure the fad of oversize grills on many current internal combustion cars have an adverse effect on their drag coefficients. Styling, in general, costs fuel economy. Aircraft are not whimsically styled; if they were, climb, top speed, range and payload would suffer.

It would be really great if you could explain to us why the wheel size has so much impact and if there are measures to compensate energy loss due to rim size e.g. Carbon Fibre or magnesium rims.

After we exit the Paris Accord, our carbon was less than when we were in it.

But... A bigger tire is worse for the environment cause you need more rubber, so only taking into account the range increase is far from realistic. Also I was expecting a discussion in terms of the wheel weight (difference between weight of the wheel + tire with different size wheels) which I expect to have a significant effect

Unless you're literally going to be racing your car, larger wheels are nearly always a disadvantage.

Regarding ride comfort -- have you considered going for aftermarket suspension? Seems like that could solve a lot of problems...

I'm a little surprised about this video. I miss in the given data from Tesla one of the most important facts. That is not the diameter of the wheel (excluding tyre). That we have. It is the width of each tyre....Is it 175 mm or 305 mm...
The next issue....The wheel shown at the start is NOT aerodynamic , just look at the spokes in that wheel and compare with those in the smaller wheel....the original black tesla wheels are more aerodynamic.
The difference in air resistance is not only related to the size of the wheel, but also to the exact shape of every detail.
Also I know that putting extra air in the wheel reduces the heating during driving and lowers the energy usage a few %.

Anyone have wheel size opinions for gas and hybrid vehicles?

Can you explain why going smaller wheel size increases efficiency? What is the engineering/math behind that? Of course keep the rolling resistance and width of the 2 sizes the same. I still couldnt figure that out. By that logic if i go to a 16" wheel, will i get even more range?

Jason, do you think it's the weight of the wheels that is affecting range so much, or is it the dimensions of the wheel?

I'm glad to hear that higher profile tires save energy. Why did he only use the front wheels? The rear wheels have some aerodynamic resistance, too.

I'm puzzled why he and others call them wheels when they are *rims* ...

Jason, what if you took off the unnecessary BBK and went down to a smaller sliding caliper? Could go with a smaller wheel and get even more range!

What is the lower bound? 2" diameter wheels are too small, but what about 15"? What's stopping us from going smaller?

2:58 you are taking the Cd for the whole car rather than just the wheels, which I imagine will be a lot higher than 0.25 Cd. Also the rolling resistance of the wider tyres will be higher in rain or on snow. (yes I am nitpicking).

Isn't it all about the width of the tire? We have two exactly same hybrids (Toyota Auris, based on Prius III) - one has 16 205/55 tires, the other 17 225/45. The car on the smaller tires gets about 20% better economy. The secret is the width of the tire - the total width of the 17 inch tires equals the width of 5 16 inch tires. In other words, driving the 17-inch Auris is like driving the 16-inch Auris with 5 wheels.

I can see it now: "Big Wheels," the racial slur of the future, hurled by drivers of small-wheeled EVs.

I dented three 19" Tesla Sports wheels in a year. These wheels are not good for bad urban roads. A typical pothole in urban cities need atleast R50 to prevent the wheel from taking impact and these Tesla 19-22" rims are not strong and the tires are too thin. I switched to 18" wheels and so far so good.

Does having larger tires affect stability and handling?

CO2 is a trace gas in our atmosphere. We could ruin the economy for negligible difference in global temps. The climate computer models on climate have been so far off why should we belive them? Climate change is all about controlling people and redistribute wealth.

Is the ultimate reason for this variance that larger tires on smaller diameter rims offer lower rolling resistance? Rolling resistance would of course be influenced by tire pressure, tread compound, and sidewall pliability. It would be interesting to hear your thoughts on tire compound and pressure in this regard. What is the hypothetically optimum rim diameter and tire size for maximal efficiency? As a side note, many endurance cyclists have been rediscovering the benefits of fatter tires on slightly smaller diameter rims, enjoying the added comfort and potentially lower rolling resistance on rougher road surfaces.

I - do you prefer to use metric system or imperial system?
Jason - yes

Fixing to switch to 18" rims and different tires on my model 3 to gain back some range and efficiency. The 19s look at nice but that's about it..

Great video as always! Does this apply to ICE cars too?

I wonder what this guys IQ is.

So in the next tour de France they'll be using bikes with very small wheels? Or less shallow tyres? No, mate. They push for ultimate efficiency. I doubt that you could be more energy efficient. Big wheels, shallow tyres.

Why no model Y analysis? Assuming it's performance is similar to the model 3, I might make a change to smaller wheels/bigger tires. I have a Model Y performance with the standard 21" wheels coming.

Monster Trucks for the environment.

So would a 15” wheel be even more efficient.
I understand we need space for good breaks but that is a solvable problem if really small wheels have a big efficiency benefit.