Originally Posted by drz
Somebody please explain to me this additional-mileage-on-the-odometer-due-to-running-bigger-wheels deal
It's not actually bigger wheels- it's shorter tires. Lower profile tires (shorter circumference) will rotate faster per 1 revolution causing the speedo to read higher and adding additional mileage.
shorter tires = faster speedo readings/ faster odometer mileage
taller tires = slower speedo readings/ slower odometer