Stock tire pressure really 49 PSI? And is it normal for one tire to run hotter?

[shiftypowers]

Hi all,

Had to put some air in all the tires yesterday. Car shows that it should inflate to 49 PSI on cold tires. Pardon my ignorance, but wouldn't that mean higher than 49PSI when the tires warm up? The tires list a 50PSI maximum pressure on the sidewall.

Also, in the car monitor yesterday, I saw that one tire (the front left) was running almost 10 degrees hotter than the other tires. Seemed odd but still showed as green.

[Jimminez@Nemesis]

Stock tire pressure is not 49 psi. What is on the door jam is the max tire pressure and not the recommended tire pressure. Always go by the manual.

For everyday driving, I run 40 front and 38 rear, then adjust if needed but can’t say I’ve yet gone above 155 mph to warrant so.

[shiftypowers]

thank you!!!

[Jimminez@Nemesis]

thank you!!!

no problem

[gpoulos]

So for ceramic brake rated 190 mph. It is indeed 49/44?


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[KJ-RS]

So for ceramic brake rated 190 mph. It is indeed 49/44?


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But that's only if you're planning to go up to 190 MPH.

If not, the recommended tire pressure is lower.

I'm going 45/42 at the moment.

I notice the TPMS is all over the place. It jumps up and down by 1.5 PSI when my other cars have always been pretty stable and within 0.5 PSI. Anyone else notice this as well?

[FBAnder]

So for ceramic brake rated 190 mph. It is indeed 49/44?


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Looks like it. Mine 21" winters were set at 35 all around then I changed them shortly after to 42/39. The 22" summers going on tomorrow will be set at 45/42.

[sdlos]

I notice the TPMS is all over the place. It jumps up and down by 1.5 PSI when my other cars have always been pretty stable and within 0.5 PSI. Anyone else notice this as well?

Yes, I have. The TPMS readings seem quite useless. I'm finding that even after setting L/R tires to the same pressure using a precision gauge (to 0.1 psi), the TPMS will read as much as a 3.0 psi difference between the two tires. I guess it's only going to be of help when a tire really is losing pressure.

[FBAnder]

Yes, I have. The TPMS readings seem quite useless. I'm finding that even after setting L/R tires to the same pressure using a precision gauge (to 0.1 psi), the TPMS will read as much as a 3.0 psi difference between the two tires. I guess it's only going to be of help when a tire really is losing pressure.

I thought it was just my fat ass resulting in a higher tpms reading often on the driver front hahaha.

[gpoulos]

I’ll drop to 45/42 tonight. Not going over 175


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[shiftypowers]

Thanks for all the responses around this. The PSI is indeed all over the place. Going to confirm this weekend with a more accurate gauge. What about the temps. Is that just a nothing burger or do others see this kind of variance in one wheel?

[sdaudiguy]

My gauge that is good to .1 has mine all set correctly but the tpms are crap. They only read in 1.5psi blocks but I can attest to them working on a rapid deflation so at least there’s that. Kinda sad their flagship cars got such outdated tech in something like this. I mean a cheap car now days has accurate tpms. It’s the little things with this car that just baffle me sometimes.

[shiftypowers]

what about the temperatures? are they all the same for you?

[FBAnder]

what about the temperatures? are they all the same for you?

Fronts run warmer than the rears for me but that seems to make sense.

[sdaudiguy]

varies on how I drive as well :)

[gpoulos]

Odd thing happened. Lowered the pressure. Tpms measures 45/42 and I’m thinking great! I go in and store the new pressure in the mmi. Now it won’t read any pressures. Slightly confused why.


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[RS6edm]

Same thing for me. Had the winter OEM wheels taken off and the OEM summer wheels put on and now the tire pressure won't read. Tried storing pressures, but no luck. I hope its an easy fix.

[FBAnder]

I got my summers swapped on today. OEM. No problems storing nor with readouts. I think I remember seeing somewhere it can take a little while for the sensors to display values sometimes after changing them.

[gpoulos]

It started measuring again this morning


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