Gear Calculator

For those new to the off-road scene or who may need to be better-versed in the mechanics of their truck’s axles, the concept of adjusting gear ratios may be unfamiliar. However, altering the gear ratios can significantly impact the relationship between the driveshaft and wheel revolutions.

By lowering the gear ratio (which may seem counterintuitive as the number is actually larger), the engine’s revolutions per minute (RPMs) will increase, assuming constant tire diameter and speed. This adjustment can have a noticeable effect on the vehicle’s performance in off-road scenarios.

At Barney Brothers Off Road & Repair, we have extensive knowledge about the effects of adding taller tires to your truck or SUV. While it may seem like a good idea to increase the tire circumference, there are several important factors to consider.

The larger tires’ circumference allows the vehicle to travel a greater distance at the same engine RPM. However, the increased space between the ground and the axle center point can lengthen the leverage arm, decreasing the amount of force applied at the end of the arm. This reduces the torque to the ground at the tire’s contact patch, making it more difficult to move a heavier wheel-and-tire combo, which demands more torque and, consequently, more fuel.

As the leading experts in the industry, we have observed that adding larger tires to your truck seldom improves economic or acceleration performance, except in the case of diesel trucks. However, even in diesel trucks, the effects of adding slightly taller and heavier tires are usually negligible, and it is essential to consider other factors before modifying your vehicle. At Barney Brothers Off Road & Repair, we can guide you through the decision-making process to ensure that any modifications you make to your vehicle will positively impact performance and reliability.