Yes, The Type Of Tires You Use Will Affect Gas Mileage - Here's What To Know

The impact of tires on cars' performance and efficiency is often underestimated. A significant amount of engineering goes into tire production, and there's a careful balance to strike. While a vehicle's body must contend with aerodynamic drag, tires face something called rolling resistance. The greater their rolling resistance, the harder an engine needs to work to keep them moving. Since an internal combustion engine requires fuel to create energy, the effort required under the hood has a direct correlation with how many miles per gallon you can achieve.

Greater rolling resistance requires that you increase the amount of rubber in contact with the ground. This can be done by either installing wider tires or lowering the air pressure of your existing tires. But why would you want to increase rolling resistance? Well, you wouldn't, except that one of the advantages of a larger rubber footprint on the ground is enhanced traction. So you can see the delicate balance that must be achieved between rolling resistance and traction. 

In one test performed by The Fast Lane Truck, a Ram 1500 did a 63-mile loop with recommended tire pressure of 43 pounds per square inch and then one with 22 psi. The underinflated tires achieved around 2 mpg less. 

While this seems simple, various aspects of a tire must be carefully adjusted, such as the sipes on a tire, to adequately handle surfaces like snow. In the case of all-season tires, make that many different scenarios.

There are situations where chunky and aggressive patterns on a tire are essential for the best performance. Take, for example, some of the meaty tires you've likely seen on off-road vehicles, which upon closer inspection feature deeper sipes or grooves in the tread. These are specifically designed to enhance grip in challenging terrain, and channel things like mud and sand around and away from the tires. For backcountry terrain, the goal is traction, not efficiency.

Those same tires on a paved surface noticeably reduce fuel economy due to the extra effort required to keep them rolling. In a Ford F-150HD fuel efficiency test between an all-terrain (Dick Cepek Radial FC-II), and an all-season (Michelin LTX M/S2) tire setup, Motor Trend found the more aggressively treaded all-terrains got 2.2 mpg less — a difference of 15% — during the run. 

In addition, knobby off-road tires are often much louder on asphalt than other types, with those deeper grooves trapping air (along with other things like rocks) as they roll. This isn't the only potential cause of those extra sounds, though — here's how to tell the difference between tire noise versus wheel bearing noise.

Choosing larger tires for your vehicle could result in fewer miles per gallon, but it depends on a variety of factors. One issue when using a larger tire is that it'll likely weigh more. One of the ways sports cars enhance performance without adding a larger engine is by reducing overall weight through lighter components and removing unnecessary parts. By adding pounds to your vehicle via heavier tires, you're asking the engine to work harder, reducing efficiency.

To illustrate this point, Scruf's Garage did a comparison between stock Jeep Gladiator tires and larger 35-inch ones. Not only were the larger tires in this case more than 40 pounds heavier per tire than stock, but a highway test loop showed a big drop from 23 mpg with stock, to just 15 mpg with the larger tires.

Sure, larger meats on a truck can look cool. But you have to wonder: Are your tires too big? And what does that mean for your transmission?