Off-road tires are essential for driving on rugged terrain. They improve your vehicle’s capability and make it a much safer operation which makes driving off-road more enjoyable. Depending on the tire, they can be designed specifically to thrive in the mud, sand, and snow, or all of the above. But what about regular streets and highways? How do off-road tires affect open-road mannerisms and fuel efficiency? The answer is more complicated than one might think.
We will preface this by stating that off-road vehicle enthusiasts typically know that they are trading in efficiencies for off-road capability. However, here are the most important things to understand about how and why the vehicle’s fuel efficiency is so adversely affected.
The Short Answer
Off-road tires can affect open-road fuel efficiency. The tires used can make a 20-percent to 30-percent difference in gas mileage, primarily due to rolling resistance — the effort required to keep the tires moving. Off-road tires generally have high rolling resistance, so they tend to decrease fuel efficiency on regular paved roads.
Other relevant factors like tire size, air pressure, and treadwear pattern also impact rolling resistance. Off-road tires greatly differ from non-off-road tire versions in all three categories. Here’s a closer look at each one.
Off-road tires are bigger and heavier than regular ones, which helps them gain more control on loose terrain and unstable road surfaces. Bigger tires are heavier because of the larger mass, but also because of construction and the materials used. Both of these reasons give the tire improved off-road performance and rugged durability. The additional size and weight equal higher rolling resistance, which increases fuel consumption.
However, not all off-road tires are totally inefficient on paved roads. All-terrain tires can still provide a smooth, fuel-efficient ride in regular and irregular driving conditions. Aggressive mud-terrain tires are not ideal for a daily driver commuter, but modern tire technology has come a long way. There will be a notable difference in gas mileage, and the driving experience will be louder than usual. But the good news is, a good tire wear life can be expected from a reputable manufacturer.
Tires with optimized treadwear design, not mud-terrain, are the best option if fuel efficiency is the top priority. Tires that have a bigger contact patch offer lower rolling resistance and still perform well in suboptimal weather conditions. They’re also less harsh on essential components like suspension, joints, bushings, and body mounts, which indirectly benefits gas mileage in the long run.
For the purpose of off-roading, enthusiasts will often lower the tire pressure to increase their contact patch and provide more traction in unstable terrain. However, lower tire pressure leads to poorer fuel efficiency on open roads. So after the trail, make sure to air up, and it is also a good idea to perform a tire inspection on a regular basis as part of a maintenance regimen.
Underinflated tires can lower fuel mileage by an average of 0.2 percent for every 1 psi drop. That number doesn’t sound like much, but it adds up fast. Even if tires are just 10 percent underinflated, you’ve increased your vehicle’s fuel consumption by 5 percent.
Additionally, underinflated tires don’t properly balance vehicle weight. Uneven weight distribution leads to more pressure on the engine, forcing it to burn more fuel to compensate for the underinflated tires. If there is only one tire supporting most of the vehicle weight, this shortens a tire’s life span and increases the odds of a blowout.
Driving with low tire pressure also heightens the risk of tire failures and accidents. Tire failures caused more than 250,000 crashes before tire pressure monitoring systems became a requirement. The Transportation Recall Enhancement Accountability and Documentation (TREAD) Act states that all vehicles made after September 2007 must have a Tire Pressure Monitoring System (TPMS).
Off-road tires are known for their aggressive, heavy-duty tread patterns. They have amazing traction but also increase rolling resistance and decrease fuel efficiency. A significant percentage of a tire’s rolling resistance comes solely from its treadwear or lack thereof. This can be demonstrated on a road race car’s tires which might have a soft compound and no treadwear pattern to minimize rolling resistance.
Aggressive tread patterns have more void space, in order to offer enhanced off-road traction. This also means a reduction in the tire’s contact patch during on-road circumstances.
Although off-road tires can bring many advantages in the mud, sand, and snow, the same can’t be said for urban and suburban environments. The size, weight, tire pressure, and treadwear of off-road tires contribute to lower fuel efficiency on the open road.
On the other hand, the driver behind the wheel will have a larger effect on fuel mileage for better or for worse. Gas prices are brutal these days, so make sure it is about smiles per miles, and best not to worry about your MPG.