[alex16]

I have used lightweight flywheels in several cars I owned in the past, 1991 Honda CRX Si, 1990 Eclipse turbo (fwd), 1995 Civic DX hatchback. All of these cars being 4 cylinders, the aluminum flywheel did offer some performance gains in acceleration but I never noticed any change in mpg, if anything it may have caused a decrease on city driving. The lighter flywheels made it much easier to stall so I would let out the clutch at slightly higher rpms with a little bit more throttle than before. I noticed no vibration changes, slightly faster reving.

I think a lightweight flywheel is a nice thing to have if your used to them but I think there is tons of better places to spend the money, places where you will see things pay for itself, such as a mechanical to electric fan conversion. I am all for aluminum, its a superior material to steel with heat dissipation and reduction of rotational mass, I will likely search for a used lightweight flywheel for my civic for the manual conversion (If I can source one for less than $100) so don't think I am opposed to the swap, I just don't think it be a mod that will pay for itself in savings.