Effect of wider tires on range

[Stefan Voinea]

I'm thinking of scrapping the 20" Uberturbines and Pirelli tires from my (soon to be delivered) M3P in favor of 19"x9.5J ET34 wheels with Michelin PilotSport 4S 265/35R19 (square setup). I was able to find plenty of info about ET, J, tire sizes and so on but nothing (at least not consolidated) about the effect on range. I'm not a range maniac but literally I have no clue on how much of hit going wider can be.
So whoever is kind enough please share your experience when it comes to range/consumption before/after switching to wider wheels and tires.

 

[Lindenwood]

All anecdotes suggest on the order of 5-15% (about 20-40 fewer actual highway miles).

Personally I think offset plays a bigger role than I have seen considered—specifically, going from a 1-inch tuck to flush probably adds a lot of turbulence around the wheel wells, beyond just an inch more width on the rubber.

But, I have no data to support and do not care enough to bother. Everything I have done—lowered (+ efficiency), wider tires (- efficiency), wheel spacers (- efficiency), front lip (+ efficiency) has largely been a wash. Though, at 75mph I found the difference between no AC and max AC to be about 100wh/mi, or about a 25-30% hit… so if you are really concerned about getting to your destination, just take off your pants in the car .

 

[gearbox]

I had no idea the AC Used that much range. Geez, it’s to hot in summer time not to.

 

[dfwatt]

I'm thinking of scrapping the 20" Uberturbines and Pirelli tires from my (soon to be delivered) M3P in favor of 19"x9.5J ET34 wheels with Michelin PilotSport 4S 265/35R19 (square setup). I was able to find plenty of info about ET, J, tire sizes and so on but nothing (at least not consolidated) about the effect on range. I'm not a range maniac but literally I have no clue on how much of hit going wider can be.
So whoever is kind enough please share your experience when it comes to range/consumption before/after switching to wider wheels and tires.

We don't have quite that set up but I have 265/30x20 (non Tesla spec PS4s) on the front and 275/30x20 on the rear (Tesla spec PS4s). It's very hard to separate out, if not impossible, the effects on aerodynamics from having a 20 inch wheel that is not particularly aero from the rolling resistance issues of a wider wheel and tire combo. Collectively, I'd say it's worth about 35-40 Watt hours a mile at least from the 18 inch aero wheels set up with Michelin MXM4, more at higher speeds, but less around town where the aero drag issues are less critical and the contributions from increased rolling resistance more critical. So it isn't simply the wider wheel, it's also the fact that you may be going from a moderately aerodynamic wheel to one that is significantly less so. All that said, the car's handling is transformed and is even significantly better than the OEM 20 PS4S Performance setup. Will pull more than one G on a skid pad (But I also have numerous MPP suspension parts!).

 

[Lindenwood]

I had no idea the AC Used that much range. Geez, it’s to hot in summer time not to.

For sure. It is just a function of

1) how efficient the body of these cars is that the AC makes up such a big portion of the power used even at speed

2) how much heat the roof glass radiates into the cabin. I have not carefully tested the difference, but I believe with my roof panels now covered, I am seeing on the order of 25-50wh/mi decrease in consumption during mid-day summer driving.

Oh and I did a 170-mile round trip yesterday with a Supercharged M3 and a Boosted M3LR. Let’s just say consumption was a little higher than normal . #rightfootbliss

 

[gearchruncher]

I have that exact setup- 19" 265 PS4S's on a 9.5" rim, +35mm offset.
With the cruise set at 65, flat ground, 70F outside, I burn about 295 wh/mi. That's about 10-15% more than rated.

Though, at 75mph I found the difference between no AC and max AC to be about 100wh/mi, or about a 25-30% hit… so if you are really concerned about getting to your destination, just take off your pants in the car .

Physics just doesn't allow this.
100wh/mi at 75 MPH means you used 7500wh more in one hour, which means it draws 7.5kW.
The heat pump in a Model 3 isn't anywhere near 7.5kW. Even the old resistive heater was way smaller than that. Most home AC units aren't 7.5kW.

 

[Lindenwood]

I have that exact setup- 19" 265 PS4S's on a 9.5" rim, +35mm offset.
With the cruise set at 65, flat ground, 70F outside, I burn about 295 wh/mi. That's about 10-15% more than rated.


Physics just doesn't allow this.
100wh/mi at 75 MPH means you used 7500wh more in one hour, which means it draws 7.5kW.
The heat pump in a Model 3 isn't anywhere near 7.5kW. Even the old resistive heater was way smaller than that. Most home AC units aren't 7.5kW.

Several others have reported the AC will draw 6-7kw as well when running hard.

Here is a recent discussion:

Is 500-1300wh/mi normal in Vegas heat?

Anyone know if 500-1300 wh/mi is normal have ac turned down to 72 degrees just myself with no load in car. It is a model 3 performance I gun it 3 of 10 times been driving mostly side street. I usto get 250-400 now it’s upto this. It is 109 degrees out and 20% humidity.

teslamotorsclub.com

 

[MasterC17]

I drove about 5,000 miles in 11 days for One Lap of America on 275/35/19 PS4S on 19x9.5 ET40 wheels and we averaged about 350-400wh/mi depending on speeds averaging from 75mph-85mph. On stock sizes with less sticky tires I'm usually down around 300-320wh/mi. So, the difference is certainly not small from what I've found.

For that reason, unless you are planning to genuinely use the extra width (autocross, road-course), I think it's extremely difficult to justify the wider setup.

 

[vogz]

I had no idea the AC Used that much range. Geez, it’s to hot in summer time not to.

Well, it doesn't most of the time. He's comparing AC completely off to cooling full blast. If you are on the highway (or even just driving on surface streets) and the interior is cooled down, it doesn't take anywhere near that much energy to maintain the temp. I've been able to do 70-80mph and use the AC set to 69 or 70 and use less than 300 wh/mi average in my M3P on hot, sunny days.

 

[Lindenwood]

Well, it doesn't most of the time. He's comparing AC completely off to cooling full blast. If you are one the highway (or even just driving on surface streets) and the interior is cooled down, it doesn't take anywhere near that much energy to maintain the temp. I've been able to do 70-80mph and use the AC set to 69 or 70 and use less than 300 wh/mi average in my M3P on hot, sunny days.

100%. This was me trying to cool down after a day of Autocrossing, where I was either in the hot car or standing on the hot tarmac the entire time, and was heat-soaked to my bones. I just happened to check the energy chart and see >400wh/mI with the AC working real hard, so I decided to run a brief experiment with turning the AC off and on every 5 miles for 20 miles. Even if I was off by 25% we would be looking at ~5.7kw which, again, aligns with other extreme anecdotes.

 

[slzeal]

Currently running 265/35/19 +29 with Michelin Pilot Sport 4S. Getting about 290 wh/mi.

Before I had the OEM 19" V2 Wheels (235/40/19 +40) that had Continental Procontact RX and I had about 270 wh/mi

 

[vogz]

100%. This was me trying to cool down after a day of Autocrossing, where I was either in the hot car or standing on the hot tarmac the entire time, and was heat-soaked to my bones. I just happened to check the energy chart and see >400wh/mI with the AC working real hard, so I decided to run a brief experiment with turning the AC off and on every 5 miles for 20 miles. Even if I was off by 25% we would be looking at ~5.7kw which, again, aligns with other extreme anecdotes.

Yup, same goes for the heat, to an even greater degree. When it's really cold and I'm blasting the heat, it's using a ton of extra power. It really does speak to how efficient the drivetrains in these cars are that just climate control alone can affect energy usage that much.

 

[Sam1]

I had no idea the AC Used that much range. Geez, it’s to hot in summer time not to.

Murders us in the desert. The old system was much more efficient with AC and it cooled better. These new heat pumps are trash for hot weather.

 

[gearchruncher]

Murders us in the desert. The old system was much more efficient with AC and it cooled better. These new heat pumps are trash for hot weather.

Care to explain the difference between "air conditioning" and a "heat pump" and why AC is more efficent?

Several others have reported the AC will draw 6-7kw as well when running hard.

This is not all cabin cooling. A lot of this is used to cool the drivetrain. You cannot remove 21kW of heat from the cabin for a long time and not be freezing inside. The solar load is only a few kW.

so I decided to run a brief experiment with turning the AC off and on every 5 miles for 20 miles. Even if I was off by 25% we would be looking at ~5.7kw which, again, aligns with other extreme anecdotes.

So in other words, you let the car cool down, turned it off, let it heat up, then turned it on again? But you estimated your energy increase from just when it was on, not the average of the on and off times? Yeah, that's not how you estimate how much load AC causes on an hour drive, and it proves the AC does not need to run all the time to keep the car cool.

 

[Lindenwood]

Care to explain the difference between "air conditioning" and a "heat pump" and why AC is more efficent?


This is not all cabin cooling. A lot of this is used to cool the drivetrain. You cannot remove 21kW of heat from the cabin for a long time and not be freezing inside. The solar load is only a few kW.


So in other words, you let the car cool down, turned it off, let it heat up, then turned it on again? But you estimated your energy increase from just when it was on, not the average of the on and off times? Yeah, that's not how you estimate how much load AC causes on an hour drive, and it proves the AC does not need to run all the time to keep the car cool.

I said “max AC.”

 

[Sam1]

Care to explain the difference between "air conditioning" and a "heat pump" and why AC is more efficent?
.

No clue what the technical difference are without Googling and pretending. After 80,000 miles in my last car and almost 30,000 in this one, personal experience is that the old one blew cold air near instantly. This heat pump thing takes 5-10 minutes to cool down, and doesn't get nearly as cold. Then, I'm looking at 150 miles of actual range in the summer now instead of close to 190 miles in the last car. Both M3P's

They may work better in the cold for people, but they absolutely do not work better in the heat.

 

[MasterC17]

No clue what the technical difference are without Googling and pretending. After 80,000 miles in my last car and almost 30,000 in this one, personal experience is that the old one blew cold air near instantly. This heat pump thing takes 5-10 minutes to cool down, and doesn't get nearly as cold. Then, I'm looking at 150 miles of actual range in the summer now instead of close to 190 miles in the last car. Both M3P's

They may work better in the cold for people, but they absolutely do not work better in the heat.

Sounds like there's an issue with your car, possibly low refrigerant or issues with the sensors. Air conditioning/cooling should work virtually the same/consume the same amount of energy from the previous system to the current one.

 

[Sam1]

Sounds like there's an issue with your car, possibly low refrigerant or issues with the sensors. Air conditioning/cooling should work virtually the same/consume the same amount of energy from the previous system to the current one.

Heard similar issues around here as well with the new systems. Heck, when I precool the car in the garage, my solar/powerwalls are showing it pulls over 5kW until the car cools down. My last car pulled 2.8kW.

 

[jackmott]

I had no idea the AC Used that much range. Geez, it’s to hot in summer time not to.

Summer time also has less dense air, I haven't noticed much net change in range for road trips. That is with a cabin temp of 74 and outside temps of 104ish

 

[The Other Dan]

After just doing the wheel calibration, my car gained a whole lot of efficiency. My trip in to work is 31mi. same time of day and traffic volume is pretty consistent. I was normally seeing about 310, after the recal, I've been seeing 270-280 for the same trip. All the normal power consumers like AC are on auto.
Percentage wise, it would usually consume about 15% for the trip, now its about 10-12%.

This is after 2mos pre and 2weeks post recal. It was like someone flicked a switch.