Speedometer Correction

If your computations were correct, you shouldn't need a correction. Were they correct?

which computations?? how do i do that?

Sergio..I'm sorry. Since this is a tuner site, I assumed you were driving a tuner car and not a SUV with a lift kit. There is a basic formula that works for cars. In your case, you're gonna need a recalibration of either your computer or the speedometer. Your best bet is to go to a site for Chevy and ask for lift and tire upsizing information.

Sorry about that. I'll search for the formula. Thanks!