How do you calculate final drive to tire size?

Here’s the formula for calculating gear ratio: (RPM x Tire Diameter Inches) / (Final Drive Ratio x Transmission Gear Ratio x 336) = Actual numerical gear ratio to the ground from every revolution of the engine.

What gears for what tire size?

Gear Ratio and Tire Size Chart

Do bigger tires raise or lower gear ratio?

If the Tires Are Bigger, the Gears Should Be Lower. Going to lower gears (ironically, a numerically bigger ratio) will increase the rpms of an engine (taking for granted the same diameter tire and going the same speed).

How do I know my differential gear ratio?

Turn the wheel TWO revolutions and count the number of driveshaft turns. The number of driveshaft rotations will help you determine your rear axle ratio. For example, if it turned 3 and a half times, it’s a 3.50:1 ratio. If it turned 4 and a quarter times, it’s a 4.25:1 ratio.

How much does tire size affect RPM?

So you’ll be increasing tire size by 10%, so you’ll decrease engine speed by 10% too. Assuming you’re running about 3000 rpm at 70 mph with the small tires, you’ll drop 10% with the big tires. 10% of 3000 is 300, so you’ll go down to 2700 rpm.

How do you calculate ring and pinion gear ratio?

The calculation uses the number of teeth in the ring gear and divides it by the number of teeth in the pinion gear to provide you with a “[result] to 1” ratio. For example, if the pinion gear has 41 teeth, and the ring gear has 11 teeth, the ratio would be calculated as 41/11, which is equal to 3.73 = 3.73:1.

Can you tell gear ratio from Vin?

While it may be possible to derive information about an auto’s gearbox ratio from its VIN, that depends largely on the information the manufacturer includes in the vehicle descriptor section (VDS) of the VIN.

How to choose the correct ring and pinion ratio?

There are several ways to select the correct ring and pinion ratio. Many methods involve some basic math, formulas, and even charts. But the easiest way to figure out the right ratio is to lower it the same percentage you increased the tire diameter over stock.

What’s the gear ratio for a tire rotation?

Check out the new comments section below! Your axle gear ratio determines how many times your driveshaft needs to rotate in order to complete one full tire rotation (a 3.73 gear ratio requires 3.73 driveshaft rotations to turn your tires 360 degrees).

What should the axle ratio be for 37 inch tires?

Increasing the 4.10 axle ratio by 16 percent would dictate the need of a 4.75 axle ratio to match the 37-inch tires. The exact axle ratio you need probably won’t be available, so it’s okay to round up when selecting the right ring and pinion. In this case, a 4.88 axle ratio would be acceptable.

How to calculate tire size for a vehicle?

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-1 (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: