CostcoFanAUS

The temperature dropped about 15 degrees last weekend and my cold tire pressure was 32 psi, which is lower than the specified 34 psi. So I had Costco adjust my tire pressure to 36 psi warm. Now the temperature rises to normal for a typical September in Houston and my cold pressure is 36 psi and warm is 39 psi. Is that too high for the oem 19" Goodyear tires? Do I need to adjust it lower? I read somewhere that for competitive driving conditions (eg, track setting), people are using higher tire pressure but not sure if it's ok for normal city/highway driving. Thanks for your inputs.

arpypat

39psi is perfectly fine for the OEM 19s on goodyear tires. You should check your tire pressure while the temp is low. I also have the 19's and I usually pump the tires to around 35-37psi, but a combination of rising temp and particle velocity (while your car is in motion) will raise the pressure. ie If you set it to 36 and start driving on the highway, you will see that the TPMS might read 37-39.

ucf_bronco

iTrader: (1)

The recommended PSI for our cars confuses me. Why the hell is it 35/35 (F/R) for the SH-AWD with 18" wheels but for the 19's with HPT it's 37/32. This is for 09-11 models.

I have aftermarket wheels with a slightly smaller sidewall so I try to run 40/35 cold.

BDoggPrelude

There's actually a big, long winded, technical explanation for all of this. To save you from all of the boring numbers, I'll keep it basic. Tires of different sizes and different load indexes reach a projected weight capacity at different air pressures. For example, the OEM 18" 96V Michelin may reach a weight capacity of 1250lbs at 32psi while the OEM 19" 94V Goodyear may need 37psi before it reaches that same 1250lb capacity. (These are just theoretical numbers. I do have an air pressure to load capacity spreadsheet for these tires in front of me). Acura may also tweak the pressures to create different handling and/or ride characteristics between the base and Advance model.

CostcoFanAUS

That reminds me of PV=nRT...

arpypat

I'm glad you know! Wish people into sports remembered science from grade school... Patriots all day!