Close Ratio vs. Wide Ratio Transmissions: Performance Sizing Guide

When selecting a transmission for racing or street use, you must choose between a close-ratio and a wide-ratio gear configuration. The difference lies in the size of the steps between adjacent gears.

Close-Ratio Transmissions

Close-ratio transmissions keep the gear steps small, which minimizes the drop in engine RPM during upshifts. This keeps the engine in its powerband, making it the preferred choice for road racing and track use.

Wide-Ratio Transmissions

Wide-ratio transmissions have larger steps between gears, featuring a low first gear for starting heavy loads and a high overdrive top gear for fuel-efficient highway cruising. This configuration is standard for daily drivers and utility trucks.

Studying gear shift drops on the automotive gear ratio calculator is a key step before performing speedometer calibrations when changing axle gear ratios.