Gear ratios set how engine speed translates to wheel speed. A high first gear multiplies torque for launch; a low overdrive top gear keeps cruising RPM down. These are typical values — exact ratios vary by model.
| Transmission | Typical 1st gear | Typical top gear |
|---|---|---|
| 4-speed automatic | 2.84 | 0.70 |
| 5-speed automatic | 3.25 | 0.75 |
| 6-speed automatic | 4.00 | 0.67 |
| 8-speed automatic | 4.70 | 0.67 |
| 10-speed automatic | 4.70 | 0.64 |
| 5-speed manual | 3.40 | 0.85 |
| 6-speed manual | 3.60 | 0.80 |
| CVT | continuously variable | continuously variable |
Final drive: multiply the gear ratio by the axle (differential) ratio to get the overall reduction at the wheels. A 4.00 first gear with a 3.73 axle gives a 14.9:1 overall ratio.
FAQ
Why do lower gears have higher numerical ratios? A lower gear multiplies engine torque more, which requires more engine rotations per wheel rotation, so first gear has the highest numerical ratio (like 3.5:1) while a highway overdrive gear has a much lower ratio (like 0.7:1) for fewer engine rotations per mile.
Work out your own numbers with the Gear Ratio and Final Drive Ratio calculators in the automotive calculators.