I bought my 01 Z28 used and it had the P235 tires non speed rated from the dealer. The previous owner had put on a new set of tires just b4 selling the car. They are still 235s (Dont ask why, I dont know either) Is there anyway I could find out the speed rating on these new tires, cause i really hope its higher than 108 of the tires from the dealer.

 

It has to say the rating somewhere on the tire. What brand are they? You might can find them on the net and get the rating code. But you should be able to find a rating somewhere on the tire itself.

 

If they're "Z" rated tires, they'll say right in the tire description, ie: P245/50/ZR16, otherwise, they'd just read P245/50/R16 if they were not Z rated. Somewhere on the sidewall it should say if they're "S", "T", "Y", or whatever the other ratings are (I'm not too sure ).

However, if your car came with non Z rated tires from the factory, even if you put on Z rated tires, you'll have to have your speed/rev limiter raised, otherwise you'll still only be able to go ~108mph (well, that's if you want to go faster, which I'm sure you would).

 

Post some of the markings from the sidewall and maybe we can help ya out.
Like was said, if the car came with 235s stock then you also have a 108 MPH speed limiter anyway though.