Originally Posted by Chip

Its the worlds simplest calculation as far as im aware.
For 4wd its :
flywheel = wheels/0.79
and IIRC for 2wd its:
flywheel = wheels/0.85

Sounds crude, but it makes SO much more sense than all these "calculated from rundown losses" figures, which are demonstrably a complete and total nonsense of course.

An ATW figure is far more indicative of the cars performance anyway and is what we should all be using really, but we are all too used to hearing flywheel quoted so it seems alien to most of us.