## What is the best axle ratio for fuel economy?

Fuel Economy Axles: For maximum fuel economy you want an axle ratio that is lower in the number of drive shaft rotations (pinion gear) for every tire rotation (ring gear). Examples of this would be a 3.21:1 and 3.42:1 axle ratio.

## Can you change the gear ratio on a semi truck?

As a recap, you could switch to a 3.08, 3.25, 3.36, 3.42, or a 3.55 and keep your current transmission, swap to a 13/18 speed, or switch to a 1.0 final drive transmission (or drive in direct) and also switch to a 2.64, 2.79, 2.85, or a 3.08.

## What are rears on a semi truck?

The axles allow the truck to carry more weight and assist in propelling the truck. A two rear-axle truck is commonly paired with a tandem axle trailer which can be identified with two pairs of wheels near the end and a kingpin at the front that connects to the hitch.

## Does changing gear ratio affect gas mileage?

Gear Ratio Effect The effect is generally minimal and will account for less than a single mile per gallon, and typically the gains are generally seen at highway speeds. The transmission gearing directly affects the fuel economy at a given speed. The engine’s rpm and fuel consumption are generally lower in higher gears.

## How do you find the gear ratio on a semi?

Method 1: Count the number of teeth on the ring gear and the pinion. Divide the number of the ring gear’s teeth by the number of the pinion’s teeth. This will give you the axle ratio.

## Does wheel size affect gear ratio?

A larger wheel would increase top end speed, a smaller wheel decreasing it. Gear ratios are gear ratios. For a given chainring tooth count moving at a given cadence, the smaller the gear in the rear the faster the wheel will turn. The larger the gear in the rear, the slower.

## What do bigger tires do to gear ratio?

When changing gears for taller tires, you are heading to a numerically higher gear ratio. The higher the gear ratio, the smaller the pinion gear. You do not want go too low in an effort to increase power to the wheels and/or relieve stress in the rest of the drivetrain.