Your axle ratio expresses the number of revolutions that your drive shaft or output shaft must make in order to rotate the axle one time. In other words, if your vehicle is listed with an axle ratio of 3.55:1–or simply 3.55–it means that your drive shaft must turn 3.55 times in order to spin the axle (and the wheels) all the way around.
Does Axle Ratio Matter?
Knowing how to answer the question, “What is an axle ratio?” is only the first step. If you’re shopping for a new or pre-owned commercial vehicle, you should know that axle ratios are important determinants of a vehicle’s performance. So, does axle ratio matter? The answer is a resounding yes, so here’s what you should keep in mind:
- Higher numerical ratios translate to higher towing capacities and lower fuel economy estimates. So, a truck with an axle ratio of 4.1 is going to be more capable than a similar truck with a ratio of 3.5. However, the latter will be more efficient.
- Higher axle ratios generally allow greater quantities of torque to reach the wheels, which can be great for moving heavy cargo or going off-road. However, since the engine needs to work more quickly to move the wheels, vehicles with higher axle ratios tend to have lower top speeds relative to other models.
How to Choose the Right Axle Ratio for Your Truck
For most Racine-area fleet operators and commercial drivers, choosing the truck with the highest axle ratio just makes the most sense! After all, you don’t want to be left wanting where power is concerned. Of course, since the cost of fuel can add up quickly, you’ll want to weigh your options carefully and choose the model that offers the best balance for your needs.
For pickup trucks built during and after MY-2010, the ‘sweet spot’ tends to fall between 3.55 and 3.73. Some trucks are offered with multiple different axle ratios, so be sure to review all of your options carefully! Lastly, axle ratio is just one of the factors you’ll want to consider, so don’t hesitate to reach out if you have any questions.
How to Find Axle Ratios
The easiest way to find an axle ratio is to check the spec sheet in your owner’s manual. It may also be listed on a sticker that you can find on the outside of your differential. However, if neither of these options work for you, here’s how to find axle ratios by hand:
- Count and Divide: Locate your vehicle’s ring gear and pinion, and count the number of teeth on each. Then, divide the number of teeth on the ring gear by the number of teeth on the pinion. This should give you your axle ratio.
- Lift and Spin: The alternative technique is more difficult, but if you can lift the vehicle and get a good look at the driveshaft, you can simply count the number of driveshaft rotations required to bring the vehicle all the way around. Mark your tire with a permanent marker, put the vehicle in neutral, and watch the driveshaft as you turn the wheel. Count the number of times that it spins until the mark you made is right back where it started.
Find Your Next Commercial Vehicle with the Lynch Truck Center
Here at the Lynch Truck Center, we want to empower you to outfit your personal vehicle or your fleet with confidence. If you know exactly what you’re looking for, fill out our vehicle finder service form! We’ll go to work to find the model that’s right for you, so you can take the next steps from your home in Northern Chicago or Milwaukee.
