What does ratio mean for a semi truck?

Axle ratio refers to the gears in a truck's differential, which connects the rear axle to the driveshaft and then the engine. This ratio expresses a truck's towing capacity and fuel economy, and the relationship between the two. New Vehicles Contact Us Heavy Truck Information.

1. What is a good gear ratio for a semi truck?
2. Is it better to have a higher or lower gear ratio?
3. Is 3.55 or 3.73 gears better?
4. Does axle ratio affect mpg?
5. Is a 3.25 gear ratio good?
6. Are 410 gears good for highway?
7. What do diff ratios mean?
8. How much does it cost to Regear your truck?
9. How do I choose final drive ratio?
10. How does final drive ratio affect performance?
11. Is 3.31 a good gear ratio?
12. Is 3.31 axle ratio good for towing?
13. Can you change axle ratio?
14. Which rear end gear ratio is best for fuel economy?

What is a good gear ratio for a semi truck?

Across 40k tandem rear applications, axle ratio choices generally range between 2.26 to 6.50, but Slesinski notes the higher range is generally reserved for vocational lower-speed segments. For on-highway linehaul, the range tightens to a fuel friendly 2.26 through 3.42 for the most common ratios.

Is it better to have a higher or lower gear ratio?

Gear ratios can be boiled down to a single statement: Higher ratios (with a lower numerical value) give better torque/acceleration and lower ratios allow for higher top speeds and better fuel economy. Higher ratios mean the engine has to run faster to achieve a given speed.

Is 3.55 or 3.73 gears better?

PERFORMANCE: The larger the axle ratio number, the quicker the truck will accelerate. For example, a truck equipped with 3.55:1 axle gearing will accelerate faster than one equipped with a 3.31 axle ratio. Similarly, a pickup with a 3.73 axle ratio will be faster than one with 3.55s.

Does axle ratio affect mpg?

Manufacturers use the standard axle ratio when setting fuel economy estimates, but fuel economy can drop by 1-2 miles per gallon when changing axle ratios.

Is a 3.25 gear ratio good?

3.25s are a good all around gear.

Are 410 gears good for highway?

This equates to a greater amount of power transferred to the wheels. Installing 4.10 gears improves the car's performance on the track but with negligible effects to the highway driving. If your car is equipped with an overdrive, you may not even notice a difference in gas mileage with the new higher gearing.

What do diff ratios mean?

Differential Gear Ratio determines the number of times the drive shaft (or pinion) will rotate for each turn of the wheels (or ring gear). So if you have a 3.73:1 gear ratio the drive shaft turns 3.73 times for every turn of the wheel. ... Lower ratios are generally desirable when going off-road.

How much does it cost to Regear your truck?

If you are looking to regear and can find an affordable shop, you could complete the whole project for around $1,500 or less. To break down the costs, you can expect a gear overhaul kit to cost anywhere from $600 to $1,200.

How do I choose final drive ratio?

To find the ideal selection, multiply the final drive ratio by the redline speed in fourth gear (152 mph) and divide that by the top track speed (140 mph). This would yield a theoretical 3.33—which is close enough to the nearest available final drive ratio of 3.36:1.

How does final drive ratio affect performance?

In general, a lower final drive ratio will lead to less torque at the wheels but a higher top speed. Meanwhile, a higher ratio will result in the opposite, i.e. more torque at the wheels but a lower top speed. Remember, this is done without any change to the power and torque of the engine.

Is 3.31 a good gear ratio?

Normally, the 3.31 would get you better gas mileage, on highway. But, with the 3.55 you will get a bit more pulling power so less time at higher RPM to get your trailer moving and when going uphill. If most of your towing is flat highway, the 3.31 should do you fine.

Is 3.31 axle ratio good for towing?

The 3.31 might be capable of towing the trailer. But if you are towing the majority of the time, you probably want the 3.55 because it will tow better and provide better fuel economy loaded.

Can you change axle ratio?

Luckily, some tuners, such as Sharkwerks, can alter the transmission's gear ratios to improve acceleration and shifting frequency. There's also the axle ratio to consider. As with the transmission, changing the axle ratio changes vehicle performance. A higher ratio means better acceleration, but worse efficiency.

Which rear end gear ratio is best for fuel economy?

The most popular rear end ratio in trucks today is the 3:55, which sort of averages towing power and fuel economy. This is a good ratio for the occasional towing or hauling individual. For a person who tows more often, and heavier loads, the 3:73 or 4:10 may be more appropriate.