This gear ratio and tire diameter chart meant to give you an approximation of ideal RPMs at highway speed (65 mph) for three situations: fuel economy, everyday driving, and increased towing power.
This chart provides values that represent a 1:1 ratio on a manual transmission.
Gear ratio and tire diameter charts are ideal for making your car as efficient as possible.
Note: Automatic transmission RPMs tend to be a little higher and transmissions with an overdrive tend to be lower.
Here’s a formula you can use to calculate your vehicle’s tire diameter:
(CROSS SECTION WIDTH x 0.ASPECT RATIO x 2 ÷ 25.4) + WHEEL DIAMETER = OVERALL TIRE DIAMETER
For Example:
235/45ZR-17
(235 x 0.45 x 2 ÷ 25.4) + 17 = 25.327″
And here’s a formula that you can use to calculate your vehicle’s rear axle gear ratio:
RING GEAR TOOTH COUNT ÷ PINION GEAR TOOTH COUNT = GEAR RATIO
For example:
41-tooth ring gear ÷ 10-tooth pinion gear = 4.10
See More:
- 6 Killer Tips For Car Headlight Repair And Installation
- Tips For Using A Car Trickle Charger
- Winter Maintenance Tips For Expert Drivers
2 Comments