TYRE SIZES TO KEEP THE SAME ROLLING CIRCUMFERANCE AS THE 16" FACTORY TYRE'S ARE FRONT 225/45/17 AND THE REARS 255/40/17 17 X 8 + 25 front and 17 x 9 +35 rear. THAT WAY YOUR SPEEDO SHOWS THE CORRECT SPEED ALS OJUST ASK YOUR LOCAL TYRE SHOP TO MATCH THE 16" ROLLING CIRFUMFERANCE TO YOUR NEW TYRES THEN U WILL BE OK