Fuel Efficiency and Tires

Larger tires are heavier and have higher rolling resistance, which decreases fuel efficiency. Smaller tires are lighter and have lower rolling resistance, which increases fuel efficiency. For stop-start traffic, smaller tires are better because they require less power to get them rolling. For high-speed freeway driving, larger tires are better because they cover the same distance with less work required by the engine.

In addition to size, weight is also a factor to consider when choosing tires. A good rule of thumb is to reduce the sidewall height by one inch for every inch you increase in wheel size.

Proper tire pressure is crucial for optimal fuel efficiency. Underinflated tires have a larger contact patch with the road, increasing friction and rolling resistance. This heightened rolling resistance translates into lower fuel economy. For example, a study by the U.S. Department of Energy found that underinflated tires can reduce fuel economy by up to 3%.

Conversely, overinflated tires can also negatively affect fuel efficiency, as they lead to a smaller contact patch and reduced traction. This can make it more difficult to accelerate and stop, which can also lead to wasted fuel. In addition, overinflated tires are more likely to overheat and wear out prematurely, which can further reduce fuel economy.

The ideal tire pressure for your vehicle will vary depending on the make, model, and year of your car. You can find the recommended tire pressure for your vehicle in your owner’s manual. It is important to check your tire pressure regularly and inflate your tires to the recommended pressure. You should also check your tire pressure before every long trip.

Tread depth is measured in millimeters (mm) and is typically indicated on the tire sidewall. The minimum tread depth required by law varies by state, but is typically 1.6 mm (0.0625 in).

Tread depth helps to reduce rolling resistance. As tread depth wears down, rolling resistance increases. This can lead to reduced fuel efficiency. It is important to check the tread depth of your tires regularly and replace them when they reach the legal minimum.

The type of tire you use can also influence fuel efficiency. All-season tires, while versatile, typically have higher rolling resistance compared to summer tires, which are designed for warmer conditions and offer lower rolling resistance. This is because summer tires are made with a softer rubber compound that conforms better to the road surface, reducing friction and drag. All-season tires, on the other hand, are made with a harder rubber compound that is more resistant to wear and tear, but also creates more friction and drag.

Winter tires, optimized for snow and ice, have the highest rolling resistance among these three types. This is because winter tires are designed with a tread pattern that helps to grip the road in slippery conditions, but also creates more friction and drag. While winter tires are essential for safe winter driving, they can also impact fuel economy.

In general, the lower the rolling resistance of a tire, the better the fuel efficiency. So, if you’re looking to improve your fuel economy, you may want to consider investing in a set of summer tires for the warmer months and a set of winter tires for the colder months.

Often overlooked, wheels also play a major role in fuel economy. If you want to further improve fuel efficiency, then looking for a set of aftermarket wheels may be the answer. Most modern vehicles are made from alloy or aluminum. Although these metals are quite lightweight compared to steel, there is room for improvement by reducing the weight of your wheels. 

Different types of construction exist in wheel manufacturing: cast, flow formed, and forged. Cast wheels are the heaviest of the three, and is how most auto manufacturers make their wheels. Flow formed wheels are a balance between the two, offering great weight savings. Forged wheels are the lightest wheels available on the market, and offer significant weight savings, which can improve fuel economy.

That said, forged wheels are the most expensive option, while cast are the cheapest.