Hello, I'm looking for some information so I can write a simple car simulation program. This program will be a simple model with 3 things: * aceleration * gear shifting (with dif. ratios for each gear) * ground resistance So that the user can do a simple simulation like a normal car in a straight line, where at some point gear shifting is necessary. Some specific questions I have at the moment: * What actually happens when the car gears shifts up? From what I've played in games like Need For Speed, when the gear is shifted up, the car's RPM reduces. But I'm not sure how this influences the whole system. * How do we determinate the gradual increase in aceleration if we keep the acellerator down? I'm guessing this is related to the current gear. Thanks for your comments.