Originally Posted by Whaazup17
I was doing some research with some formulas. If you have a 15" steel wheel vs a 15" aluminum wheel you save over 14 lbs each which mutlpy by four that is 56lbs
Wheels are rotating mass/unsprung weight. Every 1 lb reduction in rotating mass is equivalent to an approximately 8 lb reduction in static weight. With lighter weight wheels, you will benefit from increased fuel savings, quicker braking, improved tire wear and better acceleration
Also I read that every 100lbs is like 10% more fuel economy.
A great start, but not entirely accurate.
Wheel manufacturers should list wheel's moments of inertia (basically, a measurement of resistance to rotation) along with static mass. I'm really surprised that this is not done, although it might put a damper on the movement towards larger and larger wheels. A wheel that is lighter than a smaller diameter wheel can have an adverse effect on acceleration/ braking (ie, changes in angular speed) if the amount of mass is concentrated further from the axis of rotation. This effect is increased by the square of its distance.
Strictly speaking, a reduction in the total mass of the wheel will improve suspension response, but it is important to factor in inertia too.