That's cool. I tried to write a driving game back in the late 80's ... a little like Spy Hunter if anyone remembers that arcade gem. I did lose myself trying to

That's cool. I tried to write a driving game back in the late 80's ... a little like Spy Hunter if anyone remembers that arcade gem. I did lose myself trying to simulate the gearing — got caught in the circular logic problem described in the post. I wanted to simulate shifting too soon and lugging the engine (vs. shifting at too high an RPM and having thrown away efficiency/performance). But determining when you were lugging the engine depended on the engine RMP which needed to allow for the gear you were in and the current forward speed ... forward speed determined by what gear you were in, what RPM ... so we're back to RPM... Never mind possible slipping of the tire if you broke traction and spinning out or drifting.... Happy to see someone lay it all out in a blog post. (And happier still that the folks that did the game Carmageddon did a convincing enough job of all the car physics to entertain me for hours back then.)