With the Tesla Model S becoming one of the top selling luxury sedans of 2013, a myriad of Tesla aftermarket companies are looking to capitalize on range-anxious owners by launching lightweight wheels claimed to increase mileage. But does it really work?
The science behind a wheels rotational mass and its impact on driving range as well as overall performance is not a simple one. Tire/wheel weight is most crucial during acceleration and deceleration with the heavier tires & wheels producing a larger polar moment of inertia thereby requiring more energy to rotate. With mass kept closer to the rotational axis, it would have a much lower polar moment of inertia and in effect be easier to rotate. This however has little impact on range since the contact surface of the tire to the pavement largely determines the amount of friction that’s generated. The more rolling resistance the less range. It’s the same reason why soap box derby cars and long range cycling bikes have as little contract area to the ground as possible.
So before you head out and spend you hard earned dollars and the newest 22″ magnesium/titanium/super metal wheel, one should think twice since it can negatively affect your mileage and acceleration times. No bueno.