nathansmith50

tire and wheel size can also affect that.

VARifleman

Outer diameter of the tire that is. Wheel size doesn't affect it, only a change in the outer diameter of the tire will change the ratio.

rbstang

take it back from where you got it and be like what the hell did you do to my car?

tron2003

It has 245/45/17 tires on it.......

Deannostang

Probably new gears without the speedo gear changed in the tranny to compensate for rpm and new ratio. Can you break the tires loose real easy when starting up? If so, you might have 4.10's in there. Definitely need a speed gear to compensate. If your ride is a real dog out of the shoot, then you could possibly have the opposite problem: new ratio gears taken out and stock replaced without putting the stock speedo gear back in. Either way you have a problem that the proper tranny speedo gear will take care of.

Brute03

Thats what i was thinking, maybe it had say...4.10's before and nows it's back stock but still has the speedo gear for the 4.10's which is probably why the speedo is reading too slow