Vehicle speed (mph), engine speed (rpm), tire diameter (inches), trans gear ratio, and rear axle gear ratio are all interrelated. If you know four out of five of these values, you can determine what ...

What if-and believe me, this is a hypothetical-you were trying to put a wild, rare, 200-hp naturally aspirated Autech SR20DE from the hottest of the nonturbo S15 Silvias into a first-generation Miata, ...

Gearing ratios determine how many turns of the driveshaft result in a single turn of the wheels (the car's wheels, not your steering wheel). A higher ratio (e.g. 3:1) makes it easier for the engine to ...