3.54 / 3.55 and 4.09 / 4.10 / 4.11 Gears
One of the most common questions about gear ratios is: what is the difference between 3.54 and 3.55 or 4.09, 4.10, and 4.11 gears?
As our Gear Ratio Calculator explains, the gear ratio is calculated by dividing the number of teeth on the ring gear by the number of teeth on the pinion gear. Since this doesn't always end up in a nice even number, we have to do some rounding to get the final gear ratio down to three digits.
Additionally, different axles use different size ring and pinion gears that require a different number of teeth on each gear to make them turn properly. This variation in tooth number combined with a need to round up or down is what causes a discrepancy in gear ratios.