Mostly by ear with some feel. Right, you learn the sound that the engine should make (rpm) for any given MPH and gear combination.
Given the two constants of MPH and gear selection at the time of shifting you vary the engine RPM to match what you have practiced and remembered it should be for the situation.
If you can drive one by ear you can learn the sounds and feel of another quickly, but you will crash a few times as you learn each vehicle.
Grigg
