iamdub
Full Access Member
The wheel size doesn't matter. You can have 14" wheels or 26" wheels but have the same overall diameter and no change with the speedometer. It's a change in the overall diameter of the tire that affects the speedometer accuracy. What was your stock tire size? This will be on the sticker on your driver's door jamb or on the door itself. What is your current tire size? Need the complete tire size ("P275/55-R20"), not just "18" or "20"- these are the wheel (rim) sizes.
Also, at least in the pic, you're looking at the speedometer at an angle that would make the needle look slightly more ahead than it actually is reading. Look at it from straight on and see if the needle looks to be 1-2 MPH more accurate.
Also, at least in the pic, you're looking at the speedometer at an angle that would make the needle look slightly more ahead than it actually is reading. Look at it from straight on and see if the needle looks to be 1-2 MPH more accurate.
