Axle ratio
The final drive gearing between driveshaft and wheels, like 3.73. Higher pulls harder, lower cruises easier.
The axle ratio is the last gear reduction in the drivetrain: how many times the driveshaft turns for one turn of the wheels. A 3.73 axle spins the driveshaft 3.73 times per wheel revolution.
A numerically higher ratio multiplies torque, so trucks offered for towing often list options like 3.73 or 4.10. A lower ratio such as 3.08 lets the engine loaf at highway speed, trading pulling power for quieter cruising and better fuel economy. The figures on Trimslate come from the EPA's certification test records.