Gear ratios dictate how quickly your car will accelerate from a mechanical standpoint. Rear gears can also affect things like gas mileage, automatic transmission shift points, RPM when cruising down the highway and what gear you’re in when crossing the 1/4 mile traps at the dragstrip. All of these factors go into finding the right gears to make your Mustang the most enjoyable to drive. Whether you’re attempting the installation on your own or having a professional do the work for you, be sure to do your homework to ensure you get the right set of rear gears the first time.

In basic terms, axle ratio is the drive shaft or output shaft revolutions needed to spin the axle one complete turn. Axle ratio can be used in reference to either the front or rear axles, depending on if the vehicle is front wheel drive, rear wheel drive, all-wheel drive, or four-wheel drive. Several factors are affected by the axle ratio of a vehicle including fuel economy, towing capacity, and top speed. More specifically, the ratio is the number of teeth on the axle’s ring gear in relation to the pinion gear on the driveshaft.