What tire pressures do you run? (street)

[Dale_K]

I've been fooling around with tire pressures and now I'm kind of confused. What tire pressures front/rear are folks using for general street driving? I'm trying to get sort of a balanced, nimble feeling and the stock pressures make my car understeer.

When I read some old posts I get conflicting information about whether the front/rear bias gives more or less understeer.

[Johnny Danger]

Front : 235/35/19 32 psi

Rear : 275/30/19 36 psi

[landrovered]

I agree, 29 in the front is too low in my opinion, I run 17 inch tires and like between 31 and 32 in the front and 36 in the back.

[Pat]

I shoot for 34 front and 36 back when at operating temperature.

[Flavor 987S]

19" Carrera Classic wheels. PS2 tires. About 1 PSI below OEM spec, cold tire pressures. Nitrogen.

[tonycarreon]

front: 225/40-18 @ 32psi
rear: 265/35-18 @ 36psi

[986_c6]

I run close to factory recommended pressures.

[san rensho]

32/32. At 29/36 I had very noticeable lift throttle oversteer in any sweeper.

[thstone]

Street
225/45/17 29psi Front
255/40/17 33psi Rear
Hankook Ventus R-S3

Track
225/45/17 32psi cold/37psi hot Front
255/40/17 33psi cold/38psi hot Rear
Nitto NT-01

[vath2001]

Street only, 32 F / 37 R.
78%N2, 21%O2 mix

[MileHighBoxster]

I run recommended (per the manual) pressures, no problem.

[blue2000s]

Originally Posted by vath2001

Street only, 32 F / 37 R.
78%N2, 21%O2 mix

LOL, I understand it's good to put a little Ar, CO2 and H2O in that mixture.

[cas951]

I try to run factory spec but once the tire warms up tire pressure goes up signficantly during summer months. Took a long drive to Flagstaff last Sept from the Bay Area and had to drive thourgh Mojave desrt. Saw my tire pressure go up as much as 4 psi front and rear. Winter months seems it doesn't go up as much.

Now I run 30 up front and 34 at the rear.

[986_c6]

Originally Posted by san rensho

32/32. At 29/36 I had very noticeable lift throttle oversteer in any sweeper.

Lift throttle oversteer will occur in any turn, especially at the track.

[Topless]

Originally Posted by 986_c6

Lift throttle oversteer will occur in any turn, especially at the track.

+1 Lifting in the middle of a fast sweeper is like pressing the ejection button. It works every time.

Regarding the OP, I usually run 32/32 cold on the street. Running 29 up front will add a little ride comfort but not much noticeable change in handling.

[san rensho]

Maybe I'm just unconsciously compensating with steering for trail throttle oversteer, but it is very pronounced with 29/36 psi and essentially non existent when I run even pressures.

[Dale_K]

Thanks for the replies. I tried 35 all the way around but the car rode too rough over cracked pavement. What I'm trying to understand is how the front/rear bias changes understeer. I always thought a low front tire pressure was kind of a bandaid to create understeer because the car companies felt that was best for their customers. Probably they arre right, too. I think Corvairs had unbelievable tire pressures - something like 15 psi on the front and 26 on the rear.

When I bought my car a year ago I was impressed with the neutral steering and when I checked the tire pressures, the previous owner had a reverse bias with roughly 35/29. I would have kept it that way but one of the fronts was cupped and so I bought new fronts only. Unfortunately I picked a "grand touring" tire instead of a sports car tire. I'm pretty sure that is the root of my handling issues. I test drove a newish Miata and it steered ten times as good as my Boxster. The new rear tires I just put on are the same brand (Kumho) but they are more of a sports car tire. I think I need to get something better for the front.

[RandallNeighbour]

I run 30 all the way around. With coil overs, 36 in th back is just too jarring.

[Boxtaboy]

Originally Posted by vath2001

Street only, 32 F / 37 R.
78%N2, 21%O2 mix

That's only 99%. What's the last 1%?...hot air?

[jaykay]

30 / 34..........