Gear Ratio
Has anyone ever checked the rear end gear ratio on their trucks?
Axle ratio or gear ratio refers to the gears in a truck’s differential, which connects the rear axle to the driveshaft and then the engine. This ratio expresses a truck’s towing capacity and fuel economy, and the relationship between the two. Most differentials on new models list axle ratio on a sticker located on the outside. If this info is missing, you have to count the number of teeth on the ring gear and the pinion. Divide the number of the ring gear’s teeth by the number of the pinion’s teeth. This will give you the axle ratio. Axle ratio represents the number of revolutions the driveshaft must make to spin the axle one full turn. The higher the ratio, the higher the performance. The lower the ratio, the higher the fuel economy. The most popular rear-end ratio in trucks today is the 3:55, which sort of averages towing power and fuel economy. This is a good ratio for the occasional towing or hauling individual. For a person who tows more often, and heavier loads, the 3:73 or 4:10 may be more appropriate.