So i got the 15x8 ford wheels on with some new 30x9.50 A/T tires and i definitely notice the speed difference (I was expecting it). I want to say the speedometer is reading maybe 5-6 mph's lower than it should be.

Can i get this reprogrammed at the dealer or maybe something i can do? I know for some chevy and ford and dodge trucks, they sell 'hypertech power programmers' that allow you to compensate for bigger tires by plugging the programmer into the OBD2 port and fapping away on the buttons.

Thanks in advance. <img src="/forums/images/graemlins/wink.gif" alt="" />