Range efficiency from tire change

[zhu-]

How much would changing tires from the OE Michelin all seasons to a set of performance all seasons or summer tires affect the range by on an AWD M3?

Would Tesla be willing to buy back the tires (even at a discount) before delivery if I ordered a new set of tires for them to install?

 

[AlanSubie4Life]

It can reduce your range by up to 30%. 360Wh/mi is not out of the question for some configurations. There are a number of threads where this is discussed in one way or another.

It depends on a number of factors:
1) Which specific tire are you going to be using? How sticky?
2) Are you using the aeros still? (Sounds like you would be planning to)
3) Are you going to go with the same tire section width or go wider?
4) What dominates your vehicle losses (is it aerodynamics, or rolling resistance) - in other words what is your average driving speed? The faster you go, the less the tires will matter, because air resistance is a higher loss component - though the tires will always be significant for reasonable vehicle speed.
5) Driving style - probably relatively little effect, but if a stickier tire makes you drive more aggressively, it's going to slosh your energy around more, and even lead to friction braking, reducing your efficiency.
6) Is the tire diameter the same? This doesn't actually necessarily change efficiency, but it can throw off the vehicle mileage estimates a couple % if you choose to change the diameter for some reason, and confuse the situation.

In my Spark EV, changing from Ecopia tires to RE-71R tires increased my energy usage per mile around 13-20%. Definitely more than 10%. I've never carefully gathered extensive data to measure exactly (I have two identical vehicles, one with Ecopia and one with Extreme Performance Summer, so I could). But it is very significant.

 

[Jedi2155]

How much would changing tires from the OE Michelin all seasons to a set of performance all seasons or summer tires affect the range by on an AWD M3?

Would Tesla be willing to buy back the tires (even at a discount) before delivery if I ordered a new set of tires for them to install?

I think the range loss is closer to 15-20% for the tires depending on driving habits etc. Your best bet is to sell it to another individual so they'd basically be brand new. I've heard of Tesla doing the swap during delivery so you can guarantee the other party that its basically brand new and maximize selling value.

Tesla would not offer a discount to rebuy your tires. It would have to be done through a 3rd party.

 

[AlanSubie4Life]

I think the range loss is closer to 15-20% for the tires depending on driving habits etc.

I agree that's more reasonable to expect for maximum stickiness street tires, and in line with my Spark experience. However, 360Wh/mi with an AWD is definitely possible with wider (265) PS4S tires on wider rims with more poke, without aeros, with aggressive hilly driving. Those are the conditions where that (approximate) number was experienced.

 

[zhu-]

It can reduce your range by up to 30%. 360Wh/mi is not out of the question for some configurations. There are a number of threads where this is discussed in one way or another.

It depends on a number of factors:
1) Which specific tire are you going to be using? How sticky?
2) Are you using the aeros still? (Sounds like you would be planning to)
3) Are you going to go with the same tire section width or go wider?
4) What dominates your vehicle losses (is it aerodynamics, or rolling resistance) - in other words what is your average driving speed? The faster you go, the less the tires will matter, because air resistance is a higher loss component - though the tires will always be significant for reasonable vehicle speed.
5) Driving style - probably relatively little effect, but if a stickier tire makes you drive more aggressively, it's going to slosh your energy around more, and even lead to friction braking, reducing your efficiency.
6) Is the tire diameter the same? This doesn't actually necessarily change efficiency, but it can throw off the vehicle mileage estimates a couple % if you choose to change the diameter for some reason, and confuse the situation.

In my Spark EV, changing from Ecopia tires to RE-71R tires increased my energy usage per mile around 13-20%. Definitely more than 10%. I've never carefully gathered extensive data to measure exactly (I have two identical vehicles, one with Ecopia and one with Extreme Performance Summer, so I could). But it is very significant.

Is the 30% loss including the more aggressive driving habits that comes with better tires, or even if you accelerate/corner as you normally would? I was thinking either the following:

1. Keep my aero's (though with caps off), and get either one of these performance all seasons and drive year round:

https://www.tirerack.com/tires/tire...odel 3&autoModClar=Dual Motor All-Wheel Drive

https://www.tirerack.com/tires/tire...odel 3&autoModClar=Dual Motor All-Wheel Drive

2. Use aeros with all season or winter tires, and get a set of 19's with either 245 or 255 width summer tires in square setup.

If I lose 30% just from the tires while maintaining the same driving habit that might cause me to go with a more conservative setup. Though I'd feel like I'm limiting the AWD system's potential.

 

[AlanSubie4Life]

Is the 30% loss including the more aggressive driving habits that comes with better tires, or even if you accelerate/corner as you normally would?

This 30% is a worst case, and assumes very aggressive driving that you would have with better tires.

I think your proposed tires are probably not going to be as bad as an Extreme Performance or Max Performance summer tire. But you should expect to notice the difference vs. the stock tires (or not if you never had them). And you won't hit the rated range.

 

[Blur1895]

I switched from stock all seasons to same size ps4s, same pressure at 42, did not change driving style. 250 Wh/mi changed to 300, so 20% increase.

 

[zhu-]

I switched from stock all seasons to same size ps4s, same pressure at 42, did not change driving style. 250 Wh/mi changed to 300, so 20% increase.

Is yours RWD or AWD? Would love to get your thoughts on whether the extra grip is worth the range or not - especially when it comes to braking.

 

[Blur1895]

PM3- in the PNW, wet stopping and cornering did not instill much confidence. I haven’t really tested anything aggressive, but my confidence has improved. I can report back when the opportunity arises for testing the limits safely. As the temp gets closer to 40F I’ll be traveling by other means or swap to winters.

 

[AlanSubie4Life]

Is yours RWD or AWD? Would love to get your thoughts on whether the extra grip is worth the range or not - especially when it comes to braking.

Going from MXM4 (235) to PS4S (265) reduced 60-0 braking distance from 125 to 105 feet. It’s not believed that the section width makes much difference (PS4S 235 would probably give around 105 ft as well). There is a recent “Poll” thread with measured results on this topic.

 

[zhu-]

If performance tires on the aero wheels will reduce range, how does the M3P still achieve the same 310 miles range even with the heavier 20" with PS4S? Or is that range unlikely to realistically be achieved?

 

[AlanSubie4Life]

If performance tires on the aero wheels will reduce range, how does the M3P still achieve the same 310 miles range even with the heavier 20" with PS4S? Or is that range unlikely to realistically be achieved?

It likely does not achieve that range. Not sure why that is allowed per EPA regulations, I’m sure someone here knows, but I guess there is some loophole that allows a tire change to be done and the car does not have to have a separate EPA entry. There’s a spreadsheet around with (debated) modeling of the range of each vehicle. There is some question about the exact numbers due to its reliance on extrapolation of curve fits, but it’s likely not too far off. And it’s likely close enough that individual driving habits will introduce more error than may exist in the spreadsheet.

 

[Jedi2155]

I'm a conservative and efficient driver. Over 3000 miles, I'm averaging about 280 Wh/mi on my 20" summer tires which means at best I'll get about 279 miles on a 100% charge driving normally. With interstate driving ~80-90 MPH, I think that drops to about 160-220 miles on a charge.

Of course on flat road, ~50-60 mph, I bet I could hit 310 miles. All the model 3's can get 310+ miles on a charge....just depends on how fast you go . Now the same behavior on a RWD with Aero would net you almost 400 miles on a charge....

What I'm really interested (but not suggesting that people do it due to loss of grip), is running REAL low rolling resistance tires like Bridgestone Ecopia 422, Continentic PureContact w/ EcoPlus, or Michilen Energysavers. That would be interesting to me but Tesla's will NOT do well with the reduced traction of those tires. I already had traction issues on my mid-range performance EV's with LRR tires, I can't imagine how bad it'd be on a Model 3. So it'd be entirely academic

 

[animorph]

It likely does not achieve that range. Not sure why that is allowed per EPA regulations, I’m sure someone here knows, but I guess there is some loophole that allows a tire change to be done and the car does not have to have a separate EPA entry. There’s a spreadsheet around with (debated) modeling of the range of each vehicle. There is some question about the exact numbers due to its reliance on extrapolation of curve fits, but it’s likely not too far off. And it’s likely close enough that individual driving habits will introduce more error than may exist in the spreadsheet.

Not so much that the P3 does not achieve its range but that the LR RWD exceeds its EPA range. Tesla voluntarily reduced the range of the initial LR, presumably so they could advertise 310 mile range for all variants.

 

[Knightshade]

It likely does not achieve that range. Not sure why that is allowed per EPA regulations, I’m sure someone here knows, but I guess there is some loophole that allows a tire change to be done and the car does not have to have a separate EPA entry. There’s a spreadsheet around with (debated) modeling of the range of each vehicle. There is some question about the exact numbers due to its reliance on extrapolation of curve fits, but it’s likely not too far off. And it’s likely close enough that individual driving habits will introduce more error than may exist in the spreadsheet.

The 20" on the P is "optional" so they can list the EPA mileage for the 18s. Same reason they don't have to list worse mileage with the optional 19s.

All EPA numbers are with aeros AFAIK.

Which makes it interesting now that they've eliminated the P3D- and you can ONLY get the P with the 20" wheel.

 

[Jedi2155]

The 20" on the P is "optional" so they can list the EPA mileage for the 18s. Same reason they don't have to list worse mileage with the optional 19s.

All EPA numbers are with aeros AFAIK.

Which makes it interesting now that they've eliminated the P3D- and you can ONLY get the P with the 20" wheel.

Which makes me wonder if they'll have to list the new numbers in the 2019 P3D+ EPA numbers with the 20". Been thinking about this since last week lol.

 

[AlanSubie4Life]

Not so much that the P3 does not achieve its range but that the LR RWD exceeds its EPA range. Tesla voluntarily reduced the range of the initial LR, presumably so they could advertise 310 mile range for all variants.

You'd have to look at that spreadsheet I referenced (again, you can quibble with the details, but overall it is representative). The LR RWD exceeds the rated range (deliberately derated), the P3D* (aka -) and AWD about meet the range rating, and the P3D+ won't meet the 310 EPA range (with a representative drive cycle) with those sticky tires and vortex-creating wheels.

The others above have commented on the reason P3D+ can get away with it (thanks!); it will be interesting to see what they have to do next year. I guess we know why they had the P3D* unicorn in the first place now.

 

[Msjulie]

Which makes it interesting now that they've eliminated the P3D- and you can ONLY get the P with the 20" wheel.

I promised myself I wouldn't comment about P3D MINUS but I lied... there was never a MINUS, there was Performance and there was an optional upgrade package.

So yeah I do wonder what the EPA rules say about a now required upgrade package reducing the official EPA range..

 

[zhu-]

I promised myself I wouldn't comment about P3D MINUS but I lied... there was never a MINUS, there was Performance and there was an optional upgrade package.

So yeah I do wonder what the EPA rules say about a now required upgrade package reducing the official EPA range..

Is it possible to spec a P3D without upgrade package as a custom order at a service center like with FSD? Maybe some loopholes there.

 

[Need]

So yeah I do wonder what the EPA rules say about a now required upgrade package reducing the official EPA range..

I am wondering if there will be a class action lawsuit from the P3D owners next year, if the EPA range is impossible to achieve with OEM 20" tires.