What would cause an engine to slow the car more effectively via engine braking? I know the basics of engine braking -how it works, the causes of it, how to do it more efficiently, etc- and could explain it to someone fairly well. However, I don't know all the complexities. So, what would cause a car to slow more, without the use of mechanical brakes? Is it power, or torque? Does it have to do with rpm levels? Is it mainly about gearing?

Anyone have an answer? I'll repost tomorrow if the night crowd doesn't have it.

Have a Lotus for your efforts.