Efficiency/Range estimates swapping to 245/40/19 on M3P

[tyler879]

Tesla and EV noob here so appreciate any insight, this is all very new to me. I am taking delivery on a 2022 M3P in 2 weeks, but not a fan of the 20 inch Uber wheels. Debating back and forth between and 18 or 19 inch wheel swap. My personal preference is that the 235/45R18 tire is a bit beefy for my liking, but I wouldn't mind having just a slight bit of extra tire over the standard 19 inch which brought me to considering a 245/40R19 tire. Anyone done this? What did you experience in terms of ride quality, noise, and range? I understand there are a TON of variables, most of which won't make sense to me being someone who has never owned/driven an EV until now ... but in an apples to apples comparison, what sort of range/efficiency can I expect on 245/40R19's in an M3P vs the stock 235/35R20.

Thanks in advance for any and all insight.

 

[jackmott]

Tesla and EV noob here so appreciate any insight, this is all very new to me. I am taking delivery on a 2022 M3P in 2 weeks, but not a fan of the 20 inch Uber wheels. Debating back and forth between and 18 or 19 inch wheel swap. My personal preference is that the 235/45R18 tire is a bit beefy for my liking, but I wouldn't mind having just a slight bit of extra tire over the standard 19 inch which brought me to considering a 245/40R19 tire. Anyone done this? What did you experience in terms of ride quality, noise, and range? I understand there are a TON of variables, most of which won't make sense to me being someone who has never owned/driven an EV until now ... but in an apples to apples comparison, what sort of range/efficiency can I expect on 245/40R19's in an M3P vs the stock 235/35R20.

Thanks in advance for any and all insight.

• The primary thing that impacts range is the differing rolling resistance of the various tire models, not the wheels or wheel diameter
• As a secondary effect, going wider will hurt range a little due to larger frontal area.
• 245/40/19 will work fine
• You could end up with better, or worse range than you have now with that tire size, depending on which tire you picked.
• There tends to be a tradeoff where tires with great range will not have great grip, and or not last very long.

So what is it you actually want out of your tire/wheel change? More range? Better grip? More comfort? Less worrying about damaged wheels?

 

[tyler879]

• The primary thing that impacts range is the differing rolling resistance of the various tire models, not the wheels or wheel diameter
• As a secondary effect, going wider will hurt range a little due to larger frontal area.
• 245/40/19 will work fine
• You could end up with better, or worse range than you have now with that tire size, depending on which tire you picked.
• There tends to be a tradeoff where tires with great range will not have great grip, and or not last very long.

So what is it you actually want out of your tire/wheel change? More range? Better grip? More comfort? Less worrying about damaged wheels?

Thanks for the detailed response. I think 20's look good *not specifically Ubers, but a 20 inch rim) but no tire to support our pothole ridden NC roads. I'm thinking 20s will be super rough and super prone to damage here on these roads. Aesthetics matter to me, I am a car guy ... SO I know the 18s would be the smoothest ride, least prone to damage, etc. but I just like the more sporty look of the 19. Nice middle ground. I know the 235/40/19 is closer to OEM but 245/40/19 has that slightly larger sidewall that would make me feel better about the roads. I felt that maybe the extra tire diameter may be cancelled out by the smaller lighter rim for nearly equivalent range but wasnt sure what others had seen?

 

[tm1v2]

Thanks for the detailed response. I think 20's look good *not specifically Ubers, but a 20 inch rim) but no tire to support our pothole ridden NC roads. I'm thinking 20s will be super rough and super prone to damage here on these roads. Aesthetics matter to me, I am a car guy ... SO I know the 18s would be the smoothest ride, least prone to damage, etc. but I just like the more sporty look of the 19. Nice middle ground. I know the 235/40/19 is closer to OEM but 245/40/19 has that slightly larger sidewall that would make me feel better about the roads. I felt that maybe the extra tire diameter may be cancelled out by the smaller lighter rim for nearly equivalent range but wasnt sure what others had seen?

@tyler879 I think all of your reasoning there is sound. 245/40R19 on 19x8.5" wheels sounds right for you.

On the range front I expect you'll get slightly better efficiency with that setup than the stock M3P Uberturbines, even if you stay with equivalent performance tires. I swapped my M3P to 245/45R18 on 18x8.5" and gained efficiency even though I stayed in the "max performance" tire category, with tires that grip better than stock, and despite my wheels being very un-aero (thin open spoke design).

 

[DD27]

I also have a 22 M3P. What benefit, if any, do the Ubers provide over other 20 inch rims or is the difference merely cosmetic?

 

[jackmott]

I also have a 22 M3P. What benefit, if any, do the Ubers provide over other 20 inch rims or is the difference merely cosmetic?

It is just a wheel, nothing special about it.

 

[dgoodlan]

@tm1v2 can you post a picture of your setup? I just ordered same wheel dimensions for my M3P, curious to see how it looks.

 

[tm1v2]

@tm1v2 can you post a picture of your setup? I just ordered same wheel dimensions for my M3P, curious to see how it looks.

@dgoodlan You saw it already

https://teslamotorsclub.com/tmc/posts/6990143/

Edit: Those pics are at my M3P's stock height, minus 2-3mm of settling.

Edit: I do think 19" looks best on this car, but street use I think 18" is functionally even better and of course cheaper. When I did the swap (before any suspension mods) my steering felt just as responsive as stock, thanks to good performance tires.

 

[dgoodlan]

@dgoodlan You saw it already

https://teslamotorsclub.com/tmc/posts/6990143/

Edit: Those pics are at my M3P's stock height, minus 2-3mm of settling.

Edit: I do think 19" looks best on this car, but street use I think 18" is functionally even better and of course cheaper. When I did the swap (before any suspension mods) my steering felt just as responsive as stock, thanks to good performance tires.

Thanks! I knew you shared photos before I just couldn't find them when searching! What have you done to suspension? Lowering springs, coilovers?

 

[tm1v2]

Thanks! I knew you shared photos before I just couldn't find them when searching! What have you done to suspension? Lowering springs, coilovers?

Redwood Motorsports Performance Sport Öhlins DFV coilovers with Redwood's optional pillowball top hats. MPP front lower control arm bearings. MPP compression rod inserts.

(You're probably aware of this but just in case: If you lower the car much, or are doing track days or autocross, you should install camber adjustable control arms while you're at it. If you stay close to stock height and don't do track stuff then no need.)

 

[dgoodlan]

Redwood Motorsports Performance Sport Öhlins DFV coilovers with Redwood's optional pillowball top hats. MPP front lower control arm bearings. MPP compression rod inserts.

(You're probably aware of this but just in case: If you lower the car much, or are doing track days or autocross, you should install camber adjustable control arms while you're at it. If you stay close to stock height and don't do track stuff then no need.)

Thanks! Yeah I don't plan on getting too aggressive, I live in the Midwest where potholes have been known to swallow cars but want to close the wheel gap a bit

 

[nj1266]

My 2020 M3P sat on 235/35/20 wheels/tires. I monitor the max range using the Stats app. With 170 miles on the odometer, the range at 100% was 297. Close to the 299 that Tesla publishes for my car. At 500 miles, I swapped to 255/40/18 combo. The range jumped to 317 miles @ 100%. That is a solid gain of 20 miles. My next set of tire will be 255/45 which might reduce range a tiny bit, but they fill the fender well better than the 255/40 profile tires.

 

[Jangy]

• The primary thing that impacts range is the differing rolling resistance of the various tire models, not the wheels or wheel diameter
• As a secondary effect, going wider will hurt range a little due to larger frontal area.
• 245/40/19 will work fine
• You could end up with better, or worse range than you have now with that tire size, depending on which tire you picked.
• There tends to be a tradeoff where tires with great range will not have great grip, and or not last very long.

So what is it you actually want out of your tire/wheel change? More range? Better grip? More comfort? Less worrying about damaged wheels?

That's not true. Unsprung weight impact is HUGE. OP will easily save 10% in range by dropping to forged 18s. The car will also be quicker.

 

[Lindenwood]

That's not true. Unsprung weight impact is HUGE. OP will easily save 10% in range by dropping to forged 18s. The car will also be quicker

1) The acceleration difference for weight alone is on the order of 1-2% (I.e literally 3.10 to ~3.05). Lots of us have done the math to prove this.

2) It isn’t about “unsprung” weight in this case. The idea of “sprung” vs “unsprung” refers to the ability for the coil springs and dampers to control wheel movement over road undulations, which is not relevant to the efficiency discussion. More pointedly, tire rolling resistance and wheel aerodynamics are the two main factors that affect efficiency WRT wheel selection.

3) Ultimately, yes you can gain 5ish% going from Ubers to Aeros, but that is from a combination of weight, aero, and tire efficiency.

 

[tm1v2]

1) The acceleration difference for weight alone is on the order of 1-2% (I.e literally 3.10 to ~3.05). Lots of us have done the math to prove this.

2) It isn’t about “unsprung” weight in this case. The idea of “sprung” vs “unsprung” refers to the ability for the coil springs and dampers to control wheel movement over road undulations, which is not relevant to the efficiency discussion. More pointedly, tire rolling resistance and wheel aerodynamics are the two main factors that affect efficiency WRT wheel selection.

3) Ultimately, yes you can gain 5ish% going from Ubers to Aeros, but that is from a combination of weight, aero, and tire efficiency.

Ubertubines to Aeros, if you're talking about the stock tires on each, should be a 10% efficiency bump per Tesla's EPA ratings, and that sounds about right to me.

Just going down to lightweight 18s alone - non-aero, still with performance tires - was probably about a 5% efficiency gain for me. My driving wasn't and isn't consistent enough to put a precise number on it, but I doubt I would've noticed a mere 1-2% gain.

I think there's too much downplaying the impact of wheel size on this forum...

 

[tm1v2]

Ubertubines to Aeros, if you're talking about the stock tires on each, should be a 10% efficiency bump per Tesla's EPA ratings, and that sounds about right to me.

Just going down to lightweight 18s alone - non-aero, still with performance tires - was probably about a 5% efficiency gain for me. My driving wasn't and isn't consistent enough to put a precise number on it, but I doubt I would've noticed a mere 1-2% gain.

I think there's too much downplaying the impact of wheel size on this forum...

I should clarify for @tyler879, in case you come back and read more posts here, that I went to 18x8.5" ET35 wheels with 245/45R18 300TW tires. So basically same size and effective offset (with thinner M3P PUP rotor hats) as base Model 3 aero wheels, except my tires are 10mm wider. (And obviously my tires are "max performance" summer tires, which is a big difference from the efficiency-focused tires that Tesla ships on the 18" aero wheels.)

A lot of times when M3P buyers switch to 18" or 19" wheels they also go wider than stock, often 9.5" wide with 265s or wider. If you're doing autocross or track days or whatnot on the wheels, might as well get that extra grip. Wider wheels/tires obviously present a wider frontal profile, so that should harm efficiency somewhat and could counter any gain from going to 18". Totally fine, nothing wrong with that, just don't complain to me that wide 18s aren't as efficient as I was saying!

I'm guessing - just a guess! - that at constant highway speeds, my 18" wheel efficiency gain is mostly from aerodynamics of taller sidewalls / shorter spokes. My wheels aren't aero at all, but 245/45 sidewalls surely are.

I would guess the weight difference comes into play more for frequent speedup/slowdown driving, like on winding hillside roads. I do a lot of that driving and seemed to gain efficiency there too. (I can't put a precise number on it, I never tried to do a carefully controlled comparison, just it became noticeably easier to match the M3P's EPA rating.)

Again those are just guesses. If I had extra money and time to throw around (I don't) I'd love to run experiments around this. 18" vs 20" comparisons with exactly the same overall weight, to factor that out, and also a same-size comparison with ultra heavy vs ultra light wheels. In both cases using the same tires of course. I'm sure carmakers have done this...

 

[Gasaraki]

Tesla and EV noob here so appreciate any insight, this is all very new to me. I am taking delivery on a 2022 M3P in 2 weeks, but not a fan of the 20 inch Uber wheels. Debating back and forth between and 18 or 19 inch wheel swap. My personal preference is that the 235/45R18 tire is a bit beefy for my liking, but I wouldn't mind having just a slight bit of extra tire over the standard 19 inch which brought me to considering a 245/40R19 tire. Anyone done this? What did you experience in terms of ride quality, noise, and range? I understand there are a TON of variables, most of which won't make sense to me being someone who has never owned/driven an EV until now ... but in an apples to apples comparison, what sort of range/efficiency can I expect on 245/40R19's in an M3P vs the stock 235/35R20.

Thanks in advance for any and all insight.

I run 245/40/19s in the summer.

 

[jackmott]

I think there's too much downplaying the impact of wheel size on this forum...

Look man if you got a problem with Newtonian mechanics take it up with the universe =)

 

[jackmott]

That's not true. Unsprung weight impact is HUGE. OP will easily save 10% in range by dropping to forged 18s. The car will also be quicker.

Can you please show the math you did to arrive at 10% for this scenario. Also an in depth discussion on how unsprung weight affects range at all would be fascinating.

 

[Jangy]

Can you please show the math you did to arrive at 10% for this scenario. Also an in depth discussion on how unsprung weight affects range at all would be fascinating.

Many people run the Aero 18s and have reported the gains. That'll do it. Less unsprung weight