What tire pressure to run?

[Raddog]

I have 245/45ZR17 on the front (max press 51psi)
275/40ZR17 on the rear(max press. 51psi)
These seem high, what do you guys suggest? and the tires are BF Goodrich Gforce T/A KDW
Cheers Ray

[Rip Van Winkle]

I run with the weight of my car, which is 2,514. So, started at 25psi. Then see how it feels with a bit more or less.

[Ray]

Based on some advise I got on the old Forum, I started with 1lb of pressure for each 100lbs of vehicle weight. Then I adjusted up and down until I found what worked best for me. We have 245/50R/16's and I've settled on 24psi in each tire.

Ray

[Darren]

I run 22, thinking of bumping to 23. Wear has been even and traction is good.

[JKleiner]

22 ish.

Jeff

[Cone Basher]

Ray has it: 1 psi for each 100 lb or 10 psi for each 1000 of car weight is a good starting point. I run 22 front 24 rear with Hoozier A6 tires on my Coupe got Auto-x and it has worked out for me so far. I know some guys who run as low as 18 psi for extra grip in Auto-x but for a street car I think 22-24 is a good place to start. You can go up or down from there but based on what I read keep the front and rears at no more then 2 psi difference.
HTH
CB

[Raddog]

Wow thats a lot lower than I thought, and mine sitting at 29psi I thought that was low.
Cheers Ray

[Erik W. Treves]

24-26

[cobrajj]

22 front 24 rear.

[niceguy]

I'm now driving with 20 lbs in all four. I did run 28-30 lbs in rear that setting was wearing the center out. My rears are Nitto Street drag radials - soft compound at 100.

[CHOTIS BILL]

I had never heard of 10 PSI/100 pounds before but if I had used that on my DRS it would require 8.5 PSI. That is about half of what I did run. But for standard size cars that seems about right. My wife’s 350Z weighs about 3500# and I do run about 35 PSI. That is a very good thing to remember, wait I had better right that down.

Thanks,

Bill Lomenick

[ClemsonS197]

I usually do a chalk test:

How to Chalk Tires | eHow.com

[CHOTIS BILL]

I think if I wanted to go to the effort to do a chalk test I would choose to make a spirited run through a nearby canyon and then check the tire temps which will give you a better picture of what the tire is doing dynamically. It would be interesting to do both tests back to back and compare the results. But for regular street driving the chalk test may be closer to what most people do most of the time. But both tests should be done when the tires are at normal operating temperature.

Bill Lomenick

[wideglidejoe]

I've got 245/45-17's on front and 315/35-17's on back, and I run 23 psig in all 4.

[crash]

Tire pressure is determined by temperature accross the tire and wear characteristics. Simple as that.

[dukegrad98]

Originally Posted by wideglidejoe

I've got 245/45-17's on front and 315/35-17's on back, and I run 23 psig in all 4.

I have the same size tires, and I also aim for about 23-24psi cold. I have had even wear and decent traction.

Cheers, John

[thumper1]

I know I will get some flak from this, but I have a few thousand miles running around 17 to 19 psi. Includes freeway and some sport driving. Great ride. 17" wheels. 245 front and 275 rear.

[frankeeski]

Originally Posted by thumper1

I know I will get some flak from this, but I have a few thousand miles running around 17 to 19 psi. Includes freeway and some sport driving. Great ride. 17" wheels. 245 front and 275 rear.

I'm running 245 18's front and 285 18's on the rear and keep the pressure at 18-18.5 lbs on all four corners. Heat across the tires are consistent. With a short sidewall you have to adjust the pressure until heat across the tire is even.

[Michael Stora]

Originally Posted by Raddog

Wow thats a lot lower than I thought, and mine sitting at 29psi I thought that was low.
Cheers Ray

Keep in mind that your equilibrium contact area = vehicle weight/tire pressure. The vehicle is much lighter than most and has bigger tires. Both require lower pressures.

Mike