Quote Originally Posted by Zdster
Just curious, do you get better fuel economy with a lightened flywheel as it takes less energy to turn the flywheel? Anyone know/have any idea?
I think it depends on whether you are doing highway driving (fixed speed) or city driving (variable speed).

Highway driving - More inertia with stock flywheel = easier to keep speed
City driving - Less inertia with lightened flywheel = less work required to accelerate.