Model 3 Tire Pressure

[a1machinista1]

39# cold usually runs 42#-44# hot. Will use 45# for road trips.

 

[Silver Ghost]

18" wheels?

20 “ wheels.
I am thinking of going to 19 “ as costs keep adding up for the “performance” wheels

 

[Triplett]

Air is already 78% nitrogen. All gasses expand the same when temperature changes. When it's 45 your pressure will be lower. PV=NRT

Colts or Patriots fan?

 

[Feathermerchan]

20 “ wheels.
I am thinking of going to 19 “ as costs keep adding up for the “performance” wheels

I went to 18's because
I knew sooner or later I'd bust a tire or score curb rash.
The tires are very sticky but you pay for it in range and they don't last long.
The ride is pretty stiff.
The 20"wheels weigh 30 lb ea. (18's weigh 18 lb 6 oz)
The 18" make it look more like a car and less like a skateboard.

 

[Silver Ghost]

I went to 18's because
I knew sooner or later I'd bust a tire or score curb rash.
The tires are very sticky but you pay for it in range and they don't last long.
The ride is pretty stiff.
The 20"wheels weigh 30 lb ea. (18's weigh 18 lb 6 oz)
The 18" make it look more like a car and less like a skateboard.

Cannot go with 18” - the red brakes rub the rims them.
Looking for aero 19’s. Now

 

[MMBTUS]

On relatively good South Florida roads, with AC almost always on, I inflate to 39 cold and watch it increase to 42 as tires warm while driving. My lifetime 7K efficiency is 232 wh/mi. Ride quality is excellent on the 19-in wheels. Tire wear was even and slight, 1/32, at the 6K rotation. My TPMS is perfectly calibrated.

My SL550s needed new tires every 8K miles, more or less.

Just one reason I love my M3.

 

[VQTRVA]

I recently changed my tires to 255/40/19 Continental DWS06 Extremecontact's and after break in they are FAR superior in comfort, handling, ride, load carrying and I run them at 45 psi cold, I recommend them in a 255/45/18 size for your 18's if priority is comfort while improving everything els EXCEPT range, you will take a 10 to 12% hit in range

So what is the change in speedometer also?

 

[gilscales]

So what is the change in speedometer also?

Many on this forum have said the speedo is off with stock size tires, I did not check mine before I changed the the tire size, I used an iPhone speedo app and checked it with the new tires and it is spot on up to 80 mph, have not checked past that speed.

 

[Feathermerchan]

Cannot go with 18” - the red brakes rub the rims them.
Looking for aero 19’s. Now

I went with forged 18" they clear the brakes just fine.

 

[hydro 481]

Has anyone ever tested the difference in range with tires at 45 vs 39 psi? I can't imagine it would be a drastic amount. Comfort-wise though, I think it will be more pronounce.

 

[Feathermerchan]

Depends a lot on which tires and wheels you have. With the PS4S on the Performance it would be dismal. They have no sidewall anyway so also treacherous. I run 45 psi in my 245/45 18 MXM4's and the ride is fine.

 

[Firedog7881]

Has anyone ever tested the difference in range with tires at 45 vs 39 psi? I can't imagine it would be a drastic amount. Comfort-wise though, I think it will be more pronounce.

Completely unscientific -
I went from 48 all the way down to 40. At 40 the road noise is lower pitch, not necessarily quieter but it makes it less annoying for me.
I haven’t noticed any significant change in my efficiency as I consistently can still average under 200 wh/mi.

 

[dhanson865]

Cannot go with 18” - the red brakes rub the rims them.
Looking for aero 19’s. Now

You can go to 18's you just have to buy aftermarket 18" wheels. The OEM 18's won't clear, but there are others that will.

 

[Feathermerchan]

The OEM 18's can be made to clear by grinding off some molding bosses on the rear calipers but you may need spacers to clear the 3mm of the hub shoulder that sticks out from under the brake rotor hat.
I have 18" Titan 7's and love them.

 

[LakeWorthB]

Does anyone run different pressures in front/back? Was thinking of having the higher pressure in back, and lower in front to cut down on noise in front. Would TPMS complain?

 

[Feathermerchan]

Why would lower pressure in the front cut down on noise?
I'd just run the same all around.

 

[EVnut]

It is even reasonable to expect higher road noise with lower inflation.

And to answer your question, the Pressure Monitoring System won't complain if the tires are different front to back, as long as they're all above the lower threshold.

 

[LakeWorthB]

Why would lower pressure in the front cut down on noise?
I'd just run the same all around.

I was just thinking because when driving you hear the noise coming from front tires much more than the back tires.

 

[Feathermerchan]

That's probably because you are closer to the front tires.

 

[AKinDC]

Elon says "Best way to improve ride is drop tire pressure to ~39 psi. 45 psi is best range, but lower comfort."

Elon Musk on Twitter

At 39, I was getting a low pressure warning from the car.