Do larger tires get better gas mileage? The short answer is, no. Though, the real answer is a bit more complicated than a simple yes or no answer. The truth is that in many instances larger tires will not  increase a vehicle's fuel efficiency; however, there are many aspects of tires that can contribute a vehicle's gas mileage apart from the tire's size. One of the reasons that larger tires will not lead to an increase in a car's gas mileage is because they are heavier than smaller tires – every extra pound will, in essence, decrease a vehicle's fuel efficiency. Larger tires will not increase a vehicle's fuel economy because larger tires generally have a high rolling resistance, which refers to the amount of force required to move a tire from a resting position. And the wider the tire the higher the rolling resistance is and the harder the engine has to work to move the tire, thus decreasing the car's fuel efficiency.

In reality, you really shouldn't worry though about decreased fuel economy if you have or are planning to outfit your vehicle with larger tires. In most cases, the drop in fuel efficiency that someone might experience by outfitting their vehicle with larger tires is usually too small for the average person to notice.  In April 2010, Car and Driver conducted a thorough test on a new Volkswagen Golf 2.5 to see how much of an impact larger tires had on the vehicle's fuel efficiency. The Volkswagen Golf 2.5, which has a factory tire size of 15 x 6.0 inches was tested with tires as large as  19 x8.5 inches in the Car and Driver test. With the standard 15 x 6.0 in tires the Volkswagen Golf 2.5 was rated with a fuel economy of 23.3 miles per gallon (MPG) in the Car and Driver test. When the Volkswagen was equipped with 19 x 8.5 inch tires the fuel economy dropped to only 21.1 MPG – that's less than a 10% decrease in fuel economy.

Larger tires can in fact, increase a vehicle's gas mileage if the vehicle is regularly traveling with consistent speeds over 60 miles per hour. So if you do a lot of highway driving then larger tires might be the way to go. If you want the best of both worlds – large tires and fuel economy-- then take the time to carefully evaluate your tire choice. Tire weight is certainly a significant factor in determining fuel economy but everything down to the tire's tread pattern can affect a car's gas mileage. Large tires with a low rolling resistance will be more efficient than those with a high rolling resistance. And depending on your driving habits off-road tires may be more fuel efficient than all-season tires. So do larger tires get better gas mileage? Large tires won't necessarily make a vehicle have poor fuel economy and a car with smaller tires will not always be more fuel efficient, in the end it all comes down to choosing the best tire for your vehicle, large or small.

Photo by: The United States EPA
Source: Ask, Car and Driver