sorry..

 

Mine say 255/45 ZR17 99Y. 255 rather than 275.

 

Right...but the first 2 numbers indicate the size of the tire, so they can vary, the Z is the speed rating, the R stands for 'radial' and the 99Y specifies "up to 186 mph".

 

i may be mistaken,,, but i think ive seen things other than "Z" there.... my mustang had H rated tires i believe (yeah [&:]) and i thought the H came right before the rim size number

 

my 96 Z28 doesn't have a speed limiter on it, i was on a highway near my house racing a guy in a 98 Z and we were both doing around 150 mph, and i regularly stomp on the tuners around here at 130 mph or so cause they seem to have trouble getting up above 120 lol. but i'm runng z rated tires also, bf goodrich g force sports. they're apparently rated for 180 mph.

 

I thought the V8's were limited at 155?