Tire Pressure?

[PeTTey]

I have the 18" RS4 type rims with Pirelli PZero's and I was wondering what the REAL correct tire pressure should be?

Under the gas cap cover, it says to inflate (with normal loads) the rears to 30psi and the fronts to 36psi.
When I brought my car to the dealer for the 30K service, I checked the pressure and: rears were at 42psi and fronts were about the same????
Sidewall of the tire has a note not to inflate past 50psi.

I deflated the tires back to the lower specs and it did feels little mushy in comparison but that seemed like WAYYY too much of a difference! I was told when I got the car to be VERY careful with the pressure since these tires depended heavily on the correct setting!
So what gives...is the dealer trying to kill me or are the settings indicated under the filler cap not correct for my tire??

[RippleChip]

Under the cap may not be for the 18" rims, rather a 16 or 17. Make sure the chart shows the right tire size. I know on mine it says 36 and 34 for the 17 rims I have, so the 30 just seems a little low.

I'll double check the numbers after for you.

[Aman]

if it matters, I run 39psi in my 19's, cold.

[PeTTey]

The instructions under the cap DO indicate for 18" as well but are the same as the 17" for normal load. For the "heavier" load (which Audi believes is two more smaller people and some cargo according to the little pictograms!) it is a little differerent.

Just came back from lunch (93 Octane at 83 cents...wooo!) and just felt like the steering was too mushy??

[RippleChip]

I run my 17s at ~35

[kontesto]

just got 91 for 78 :D

[jefferson88]

there is an actual formula for tire inflation that involves the weight of your car but I can't remember what it is....

[PeTTey]

I guess I will put them in the high 30's but I was worried that over inflating those low-profile tires could be bad?? ![confused]

Should the rears be THAT much lower than the fronts or should I just do 'em all the same?

Thanks again!