lightweight wheels model 3 performance 0-60 testing

[Lindenwood]

Yeah, removing the weight at 24" on a 20" wheel would be great. It's just that it's physically impossible. Yes, I am aware some of the mass is in the tire which is outside this, but the majority of the tire weight is in the tread, and that isn't changing much. A LOT of your weight savings will be far inside the 18" diameter of your 18" wheel.

You're also over-estimating the Uberturbine weight by 5 lbs:

2021 Uberturbine Wheel Weight

The other day I wanted to compare the weight of the 2021 M3P 20" Uberturbine wheel & tire to the summer wheels that I use on my 2018 LR RWD. Uberturbines: - Stock wheel w/ 2021 M3P, 20x9, +35mm ET - Stock 235/35-20 Pirelli P-Zero - 690 miles - Condition: New - No wheel lug cap - Weight: 54.5...

teslamotorsclub.com

You're realistically going to save 15lbs per corner, which is 1.4%. Your MMOI will save you another 1%.

Tire diameter is not HP in the way lighter tires are. It's just changing what gear you are in which will change acceleration at different points in the speed curve, but it will always have tradeoffs.

I specifically said against my 28lb 255/35R20. 32+28=60.

I also specifically said going down to a 22lb, 225-width tire, which means that weight savings (as you said) is going to indeed be close to the tread, which would be at around a 24”+ radius.

I understand you are passionate about your position, but zoom out a little and understand it is highly improbably you are the only intelligent person in this thread. Maybe re-read the things you are quoting a bit more carefully before you dismiss them as “impossible.”

Of note, If you cut the tire diameter in half, such that the motors hit their speed limit out at 81mph actual speed, the actual force at the contact patch would be greater across that entire speed range until hitting 81mph. Thus, the 4% acceleration advantage I cited still stands (since we are mostly talking about 0-60 or, at most, 0-120ish acceleration).

 

[Sam1]

I understand you are passionate about your position, but zoom out a little and understand it is highly improbably you are the only intelligent person in this thread. Maybe re-read the things you are quoting a bit more carefully before you dismiss them as “impossible.”

I disagree with his personal opinions on a regular basis, but, respect most of his technical content because he is spot on most of the time.

 

[Lindenwood]

I disagree with his personal opinions on a regular basis, but, respect most of his technical content because he is spot on most of the time.

The thing is, I actually have agreed with much of what he has said. However, in the recent example when he was talking like I was completely out of line, in fact it was simply him misunderstanding my specific assertions.

 

[Sam1]

I can hit 1.1g regularly with the car, got my 2019 to hit 1.2 once, but was never able to replicate it...but 2019 and 2021 is easy to hit 1.1

As for traction, I mistermed that. I meant the cars can be traction limited on some surfaces, but the computer is limiting the acceleration rate overall. Most of the dragy numbers are done on the street, very few are done on the track. but again, you're making assumptions based on data that you don't have complete knowledge of. What were the atmospheric conditions, road conditions, battery conditions, etc of those dragy runs? It's kind of like using confirmation bias to justify an outcome, based on the results of the outcome you already have.

apparently I lied with this, I swore the 21 would do 1.1g too and it will not. The 2019 has no issue doing it, but they've really limited that punch off the line with these new ones. Just went out and tried 10 launches and couldn't get it over 0.9g, even tried to swing the weight by doing a brake in full regen to a launch at 10 and 15 mph and no matter what it won't touch 1g.

 

[mpgxsvcd]

You shouldn't make assumptions on things you don't know about. Because that 2.97 second 0-60 time was done on the stock 19" wheels with OEM continental all season tires and with lightweight rotors.

After I installed the lightweight wheels to reduce the total weight from 20 pounds to 48 pounds lighter, my 0-60 times slowed down, even though I went to stickier tires.

The 0.05 variation in times could easily be written off by environmental differences.

Boom.

<ps> those times have been posted in multiple places, because I was the first person to get a sub 3.0 second 0-60 time recorded and I was pretty happy with it.

So you are saying lighter brakes gained you the time difference? Fine. You lightened up something and your times decreased by .07 seconds and yet you claim there is no difference? Your own data betrays you.

Every single time someone reduces their rotational mass on Dragy their times improve. It isn't a crazy .5 second time difference like when they put the super small and incredibly light wheels and tires on the Model Y. However, it is almost always in the range of .07-.08 seconds 0-60 mph and even your own data confirms that. I am just surprised you still stick to your story about it having absolutely no affect at all when you demonstrated it with your own car and continue to deny it.

You say that a .05 variation can be written off. However, what you aren't acknowledging is that your times were pretty much at the limits for a "Stock" Model 3 Performance already. Then you changed the rotational inertia and you bettered those times and were excited about that. I can't fathom why you continue to say it produces identical results when you showed that it does?

 

[gearchruncher]

I specifically said against my 28lb 255/35R20. 32+28=60.

I also specifically said going down to a 22lb, 225-width tire, which means that weight savings (as you said) is going to indeed be close to the tread, which would be at around a 24”+ radius.

In the same post, you also specifically said this, which is what I was reacting to, and why I used the 60 and 40lb masses in all my calculations.

That said, I am intrigued about the idea of going from my 60lb, 27” wheel/tire combo down to a 40lb, 26” combo (I.e. an 18lb 18x8 with a 22lb 225/45R18). Relative to what I am experiencing, that could net a good 6-8% increase in effective power, or about 30+hp, which I expect would certainly be perceptible.

You also then immediately asked this question, which does not sound like someone that has done all of the math:

Does this account for the basic loss from a linear standpoint? As in, losing 10lb per wheel of mass means the motors no longer have to either spin up the mass or simply push it down the road?

Apologies if I offended, but the internet is full of people that have been led to believe that light wheels and tires will have some magic, massive effect, and the math just doesn't support that.

Look forward to your real world performance tests.

 

[mpgxsvcd]

But, as I said before, all you have to do to prove me wrong is go and buy a set of wheels, tires, and rotors for a few thousand dollars and start logging times. There's no reason for me to argue it with anyone, you're not spending my money, so feel free to buy and do anything you want

My wheels and tires get delivered tomorrow. I have 13 1/4 mile track runs logged with it stock at 4315 pounds including me. I also will have the ability to charge to ~98% and then test at the track back to back with the only change being the wheels and tires. I can log battery temps, times, weights, DA, and do a rolling dyno for each run. If that doesn't demonstrate what is going on I don't know what would.

 

[mpgxsvcd]

I can hit 1.1g regularly with the car, got my 2019 to hit 1.2 once, but was never able to replicate it...but 2019 and 2021 is easy to hit 1.1

As for traction, I mistermed that. I meant the cars can be traction limited on some surfaces, but the computer is limiting the acceleration rate overall. Most of the dragy numbers are done on the street, very few are done on the track. but again, you're making assumptions based on data that you don't have complete knowledge of. What were the atmospheric conditions, road conditions, battery conditions, etc of those dragy runs? It's kind of like using confirmation bias to justify an outcome, based on the results of the outcome you already have.

So if I do a 0-60 mph run down a hill with my lighter wheels and tires you are saying I won't beat your best 0-60 mph time? If it limits acceleration then going downhill shouldn't make it faster than the fastest car, right?

 

[M3Pdude]

Well there's 15 min of my life I will never get back..

 

[Sam1]

My wheels and tires get delivered tomorrow. I have 13 1/4 mile track runs logged with it stock at 4315 pounds including me. I also will have the ability to charge to ~98% and then test at the track back to back with the only change being the wheels and tires. I can log battery temps, times, weights, DA, and do a rolling dyno for each run. If that doesn't demonstrate what is going on I don't know what would.

You're new here. A bunch of us have been doing what you've been doing for 3-4 years now. There's is absolutely nothing you've mentioned that is any different than anything we've already tried. But go and enjoy yourself! Just keep in mind that there will be variations in your times occasionally, so be honest with the results and don't try to use your slowest oem setup time with your fastest non-oem setup time to falsely prove a point.

 

[Sam1]

So you are saying lighter brakes gained you the time difference? Fine. You lightened up something and your times decreased by .07 seconds and yet you claim there is no difference? Your own data betrays you.

Every single time someone reduces their rotational mass on Dragy their times improve. It isn't a crazy .5 second time difference like when they put the super small and incredibly light wheels and tires on the Model Y. However, it is almost always in the range of .07-.08 seconds 0-60 mph and even your own data confirms that. I am just surprised you still stick to your story about it having absolutely no affect at all when you demonstrated it with your own car and continue to deny it.

You say that a .05 variation can be written off. However, what you aren't acknowledging is that your times were pretty much at the limits for a "Stock" Model 3 Performance already. Then you changed the rotational inertia and you bettered those times and were excited about that. I can't fathom why you continue to say it produces identical results when you showed that it does?

I am saying exactly that (will put it in caps for you) - LIGHTER ROTORS DID NOT CONSISTENTLY DECREASE MY 0-60 TIMES - You are referring to a single uploaded data log. Not the other 50 or 60 I did that had zero or negative changes.

Stop hyperfocusing on a result that the person who recorded it told you to stop hyperfocusing on. Good grief. This is like a scientist telling you their findings were skewed, but a person not involved with the research, telling the scientist that his findings are factually proveable lol.

 

[Lindenwood]

It's not.

4,000 lb car @ 70 MPH: 888,000 joules
1 lb @ 70 MPH, 17" diameter: 182 joules
So each pound you take off a wheel is 730 joules at 70 MPH, out of 888,000. 0.09%.

Stock uberturbines are 32 lbs. SV104's are $6000+ per set, but sure, they weigh 10 lbs less (so do $250 wheels). That's a lot of coin for 1%.

No way you are noticing 1% reliably, and again, as the power falls off below 50% power, you have no idea if the wheels made any difference since the power is changing so fast vs SoC.

Maybe someone that spent $6000 for wheels that don't even list their weight as a spec would be kinda biased about how much performance they gained. Glad you like your wheels though.


Fair. So 1 lb is 182 joules turning each, and 222 joules forward (like any single pound in the car is). Yes, there is literally more energy in the linear mass than the rotational mass.

Tinkered with my own math as well. Even using a whopping 10lb per corner at 24” diameter, we only save about 1.5% of the accelerational energy, or 2.5% total once you factor in both linear and angular accelerations. Interestingly, going to the not-uncommon 27” tires (I.e. 255/35R20), we also lose about 2% of effective wheel torque.

This +\- 2% is about the same as a ~8-degree (F) change in battery temp at a given SOC.

Overall, going from the factory Performance Uberturbines to light weight wheels and tires might technically be perceptible, but not significant, as it would feel like a ~10-15 HP gain in a 550hp vehicle. Of course, going down to a 26” tire almost doubles the effect, so you could approach a 5% “increase” with super-light wheels and undersized tires, which would feel like an extra 20-25HP.

In any case, I think the point still stands that shaving wheel weight is far less significant than we would all love to believe.

*edit*

And to be clear, I am not sure it is possible to reduce the wheel and tire combo by 10lb at a 1ft radius (I.e. maybe with some light 225-width tires), so the actual numbers are indeed going to be closer to what gearcruncher showed (closer to perhaps 1.5%, or about 8-10HP effective difference). This is the difference we experience between about 80 and 90% SOC, or about 10 degrees F difference in battery temp. Again, if I am really paying attention I can maybe feel it, but it is really not significant.

@gearcruncher, only a few pages ago I literally did the same math as you did and reached the same conclusion…even citing you in my post that I agreed with what you are saying. Then I use the exact same principles in a more extreme, hypothetical example and you act like I am coming out of left field?

Again, if I lowered my final ratio by 4% (27” to a 26” tire), and reduced raw mass by 80lb (20lb per corner given my 32+28lb wheel/tire combo), that is already a potential for 6% faster acceleration in my extreme case. Thus, in postulating a “6-8% improvement” I was literally only attributing 0-2% potential gain from the reduced rotating mass, which is exactly in line with everything else we have both said.

 

[oreobbq]

Alright fellas, what's the answer? 14 pages later it seems like any performance gains from reducing rotating mass are very minimal but still there?

 

[jackmott]

Alright fellas, what's the answer? 14 pages later it seems like any performance gains from reducing rotating mass are very minimal but still there?

It isn't that complicated but people can't handle even a little nuance:
For a 0-60 time, a lot of it is acceleration limited by software, but a little bit isn't. So if you reduce weight (rotational or not) you may go a tiny bit faster. But given that people overestimate how much rotational mass matters *in general* multiplied by the fact that 3/4 of your 0-60 run is software limited anyway, the gains are tiny and hard to reliably measure given all the other noise in the test (battery temp, wind, traction luck, state of charge, etc)

 

[M3Pdude]

So is this where science ends and art begins? lol

 

[jackmott]

So is this where science ends and art begins? lol

Science is hard. Use to be an artist had the fastest design for land cycling speed record vehicles The Diablo Varna: https://herbeat.com/wp-content/uploads/2015/01/Unpaced_Biking_Varna_Diablo_III_1.jpeg, it was years and years before actual engineers scienced hard enough to beat him. They did eventually though.

Sometimes art is enough

 

[mpgxsvcd]

You're new here. A bunch of us have been doing what you've been doing for 3-4 years now. There's is absolutely nothing you've mentioned that is any different than anything we've already tried. But go and enjoy yourself! Just keep in mind that there will be variations in your times occasionally, so be honest with the results and don't try to use your slowest oem setup time with your fastest non-oem setup time to falsely prove a point.

For the record here are my fastest times. I believe these to be the fastest stock times my 4315 lb 2022 Model 3 Performance can do. That is because I logged a rolling dyno run throughout this entire dragstrip run. It peaked at 447 KW combined @ 55 MPH. That is the highest output I have recorded with my car and conditions were perfect. If you or anyone else thinks my particular car can do better without any changes from stock then I am all ears.

None of that past data should be relied on though. I will do back to back runs only switching out the wheels and tires and monitoring temps and Power output to keep them equal. That is the true controlled test that will answer the question once and for all.

 

[Sam1]

For the record here are my fastest times. I believe these to be the fastest stock times my 4315 lb 2022 Model 3 Performance can do. That is because I logged a rolling dyno run throughout this entire dragstrip run. It peaked at 447 KW combined @ 55 MPH. That is the highest output I have recorded with my car and conditions were perfect. If you or anyone else thinks my particular car can do better without any changes from stock then I am all ears.

None of that past data should be relied on though. I will do back to back runs only switching out the wheels and tires and monitoring temps and Power output to keep them equal. That is the true controlled test that will answer the question once and for all.

View attachment 815145View attachment 815146View attachment 815147

Not arguing, but you're also making the same mistake I made years ago. that 447kw is not combined powerband, that is the peak power of both motors, added individually. Peak power of each motor is independent of each other, meaning the car will never put down an actual 447kw.

Again, you're not doing anything lots of us haven't already done, and had this same discussion on the message board here about multiple times. Not trying to steal your thunder, but there's a reason why most people are telling you they won't make a consistent difference.

Also I just uploaded a 2021 oem run with 3.22 0-60 completely stock. so 0.01 better than your 3.23. And when you upload a 3.21, I'll upload a 3.20. No one has a special car, these are all the same specs.

 

[mpgxsvcd]

Not arguing, but you're also making the same mistake I made years ago. that 447kw is not combined powerband, that is the peak power of both motors, added individually. Peak power of each motor is independent of each other, meaning the car will never put down an actual 447kw.

Again, you're not doing anything lots of us haven't already done, and had this same discussion on the message board here about multiple times. Not trying to steal your thunder, but there's a reason why most people are telling you they won't make a consistent difference.

Also I just uploaded a 2021 oem run with 3.22 0-60 completely stock. so 0.01 better than your 3.23. And when you upload a 3.21, I'll upload a 3.20. No one has a special car, these are all the same specs.

Actually that number is me adding the instantaneous power that is reported for F.Motor and R.Motor. That isn't the max possible value that is reported. Now we all know it isn't putting down 447 KW to the ground. That would be 608 HP. However, it does indicate a maximum value of what the car is reporting it is putting out at any given time. Please note that I am not using the max possible value there. That number was 453 KW when I tried it today. I have never seen it report an instantaneous value that high while doing a pull.

You keep saying this has all been done before and yet there is no data for it? It is simply a few people repeating over and over again that it doesn't matter. Yet every single Dragy result and DragTimes Drag slip says otherwise. I just simply want to actually see some evidence. If these tests have been done before then where is the data?

I have been to the track 4 times and the results I posted above were the best I could do stock. If I can match your best time simply by adding lighter and smaller wheels then I will be satisfied and I will have the data to demonstrate it. If not then I have wheels that can actually withstand potholes and I think they look better. Probably will have to lower the car eventually though. It didn't change the ride height. It just made the car look like it needed to be lowered.

 

[EVolv3d]

For the record here are my fastest times. I believe these to be the fastest stock times my 4315 lb 2022 Model 3 Performance can do. That is because I logged a rolling dyno run throughout this entire dragstrip run. It peaked at 447 KW combined @ 55 MPH. That is the highest output I have recorded with my car and conditions were perfect. If you or anyone else thinks my particular car can do better without any changes from stock then I am all ears.

None of that past data should be relied on though. I will do back to back runs only switching out the wheels and tires and monitoring temps and Power output to keep them equal. That is the true controlled test that will answer the question once and for all.

View attachment 815145View attachment 815146View attachment 815147

Thanks for sharing!

As expected, these are nearly identical to my '22 M3P times. My best 0-60mph is 3.22 (on the street). My best 1/8 mile time is 7.32 @ 96.26mph. I haven't done many 1/8 mile passes, but there's not much room for improvement (maybe a few hundredths).

I have tons of 0-60 passes logged on my Dragy in various conditions. I consistently get low to mid 3.2x on the street in ideal conditions. It's very repeatable and I have plenty of data to analyze and get a solid average for various conditions. I'll be repeating all of my testing once I get the new wheels installed. It should be pretty clear if there's any improvement. If I'm able to consistently break into the mid to high 3.1x range then they "helped". Will I ever be able to feel that difference? No.