roadcaqpt

What ya'll running frt rear?

1bdvet

Check your drivers door jam, they have tire pressure recommendation.

John A. Marker

35 both front and rear.

peyc2

33 front 35 rear on nittos 555 275 40 17 on 17 x 9.5 front and 315 35 on 17x11 on rear

WW7

..Same here....WW

roadcaqpt

Thanks folks for the responses. I was running 45 frt an rear. blew a side wall on rear an guy at tire store asked what i was running. Said my be due to launches and the occasional burn out weakened it.

FASTAZU

45psi is way to high!! I runs 34F & 32R

Wathen1955

Sticker on my door says 32, but I run 33 all 4.

JrRifleCoach

45 may sound high but it is not dangerous.
Look at the max pressure rating on the sidewall.
My Kumho's 285/40/17 are rated at 51 psi.
Why anyone would run a pressure that high is beyond me.

Just curious did the tire store check the age (DOT) on the tire?
It's a four digit number identifying the year and week of that year the tire was manufactured.

AirForceOne!

rocco16

Door jam says 30psi front and rear on mine and those are good pressures. I went to 35psi on a fast mountain run one time and loss of traction was both noticeable and scarey. Never again.

Going higher than recommended is not dangerous to the tire, but is quite dangerous for the bodywork.

Those of you who do not regularly approach the cornering limits of your C4 probably won't notice the problem with going 5psi over on tire pressures, but when you're running on the ragged edge, it makes a HUGE difference.

QCVette

I have always run 32 front and rear and then adjusted based on tire wear/contact patterns. On my C4's that seemed pretty close with stock size tires.

JimGnitecki

I run 32 psi at all 4 wheels, as I have found that going higher makes the ride unnecessarily stiff, even in the "middle" setting of my FX3 suspension.

I'd run 30 psi (have tried it and liked it), but I am on an out of town contarct assignment right now, and so checking and topping up tire pressure is less convenient than when at home (have my own compressor at home).

The tires on our C4s are so wide that you need much lower air pressure than you think to get a good contact patch, and the tire sidewalls on the factory-recommended street tires are stiff enough to prevent squirm. I suspect that running higher pressures will result in worn centers on the tread.

Jim G

peyc2

I found running 35 in the front I was getting some under steer on expressway ramps. Going to 33 front 35 rear it seamed to be less. I'm on Nitto 555 275 40 x 17 front and 315 35 x17 on the rear wheels are ZR 1 replicas 17x9.5 and 17x11

roadcaqpt

Wow we are all over the place. I will do 35 as max and see how it goes. The tire date code was 0806. Tire was a General 275/40 zr17 rated at 50psi.

Thanks again

96GS#007

7 year old tire It was toast 2 years ago. Just because it has tread left doesn't mean it's ok.

Also keep in mind that you have to account for an increase in tire pressure due to heat when driving. On a typical day with a little interstate driving, most will pick up 2-3 psi. On a race track (road course), 8-10 psi isn't unusual. Do stupid sh*t and 4-7 on the street is possible.

30-35 on a street car is the typical range. Check for even tire wear (ie over-inflated tires will wear faster in the center while under-inflated will wear faster at the edges) and go from there.

peyc2

What 96gs007 said is right. See how the car acts. Nothing crazy but understeer/oversteer and tire wear are good indications that you are in the right range. Door guide is for factory original tires. Almost no one is on those anymore, as size and width have changed. My original tires were 255x50 16 inch on 8.5 wheels. Those are in the corner, with 10 yr old tires that I would never want to drive on. No cracks, but i would not trust the sidewalls.

rocco16

Door guide is for factory/original sized tires. My original sizes/widths have not changed, therefore door guide is applicable.
Inarguable: every psi increase means a smaller footprint, which usually means less traction. Other factors do enter in, but them's the facts.

Hot Rod Roy

I've tried a variety of tire pressures in my '84, and I find the best handling at 36 front, 32 rear. I'm running 255-50-16's on 9.5" wheels.

Old Ben

Another 32psi all around.