Correct tire pressures for Pirelli P zeros

claycourter01 · 03-12-2016, 08:34 PM

I have a 2012 335i coupe (M-sport) with 19" wheels and Pirelli P zeros. I have always kept them at the pressures listed on the door jamb, 38 front and 45 rear.

I recently had the car at the dealer, just for a state inspection, and noticed that when I picked up the car it was handling much better. Corners better and feels like it has another 20 HP. I could not figure out what it was and then checked the tire pressure and discovered the dealer had set it at 45 all around.

The car sure feels better to me; is it OK to keep the pressures at 45 all around?

lens · 03-12-2016, 09:05 PM

Quote:

Originally Posted by claycourter01

I have a 2012 335i coupe (M-sport) with 19" wheels and Pirelli P zeros. I have always kept them at the pressures listed on the door jamb, 38 front and 45 rear.

I recently had the car at the dealer, just for a state inspection, and noticed that when I picked up the car it was handling much better. Corners better and feels like it has another 20 HP. I could not figure out what it was and then checked the tire pressure and discovered the dealer had set it at 45 all around.

The car sure feels better to me; is it OK to keep the pressures at 45 all around?

....45psi is WAY too high, especially since tire max psi is 50psi.

That's just asking for a blowout as your tires heat up as you drive.

I run 36 front 38 rear if empty car and 38 front 40 rear if full.

jhuber · 03-12-2016, 09:49 PM

Isn't the max PSI printed on the tire a cold tire value?

Orient330iNYC · 03-12-2016, 11:51 PM

Quote:

Originally Posted by chaungo

....45psi is WAY too high, especially since tire max psi is 50psi.

That's just asking for a blowout as your tires heat up as you drive.

I run 36 front 38 rear if empty car and 38 front 40 rear if full.

Quote:

Originally Posted by jhuber

Isn't the max PSI printed on the tire a cold tire value?

the max pressure on the sidewall is the max COLD pressure. this accounts for the temperature induced pressure increase when the tire is HOT plus running at max load for the tire.

inflating to 45 COLD is within the tire spec and NOT asking for a blowout.

lens · 03-13-2016, 12:22 AM

Quote:

Originally Posted by Orient330iNYC

the max pressure on the sidewall is the max COLD pressure. this accounts for the temperature induced pressure increase when the tire is HOT plus running at max load for the tire.

inflating to 45 COLD is within the tire spec and NOT asking for a blowout.

But the question is, would you really run 45psi to max psi daily?

03-12-2016, 08:34 PM	#1
claycourter01 Private First Class 50 Rep 145 Posts Drives: 2023 M5 Competition Join Date: Nov 2005 Location: Southeastern US iTrader: (0) Garage List 2023 BMW M5 Competi ... [0.00]	Correct tire pressures for Pirelli P zeros I have a 2012 335i coupe (M-sport) with 19" wheels and Pirelli P zeros. I have always kept them at the pressures listed on the door jamb, 38 front and 45 rear. I recently had the car at the dealer, just for a state inspection, and noticed that when I picked up the car it was handling much better. Corners better and feels like it has another 20 HP. I could not figure out what it was and then checked the tire pressure and discovered the dealer had set it at 45 all around. The car sure feels better to me; is it OK to keep the pressures at 45 all around?
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03-12-2016, 09:49 PM	#3
jhuber Lieutenant 66 Rep 448 Posts Drives: 2013 335i Join Date: Feb 2010 Location: Leavenworth, KS iTrader: (2)	Isn't the max PSI printed on the tire a cold tire value?
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