I had 16 inch rims on mine and my stupid ass friend whop had the car before me put low-pro tires on and mine was reading about 7 MPH off on my 93 dx sedan. I have 205/50/16 on it now and my mileage is perfect. I would reccomend a bit smaller on the width because my tires didn't quite clear the rear fender wells with all stock suspecnsion.