Do Bigger Tires Affect MPG?

Last Updated on March 25, 2023 by Paul S.

There are many reasons to get bigger tires on your vehicle. Getting your vehicle to sit higher, get over larger objects on the road, or even just for a more aggressive look are some of those reasons. 

Bigger tires can have a negative effect on a vehicle’s fuel efficiency or miles per gallon (MPG). This is because larger tires can add more weight and increase rolling resistance, which requires the engine to work harder to maintain speed and ultimately burns more fuel.

In addition to the increased weight and rolling resistance, larger tires may also require a change to the gearing of your gears in your differential. This is necessary to keep up the efficiency of your vehicle. When you add a lot of weight to the vehicle you may want to look into regearing because the vehicle was designed to be most efficient at a particular range of weights. To keep it short the vehicle’s engineers designed a car to work one way with specific-sized tires and for the most part for a specific weight. When you start to mod your vehicle (which you should do!!) then you are throwing your vehicle out of spec. 

Cross Section of a Differential

However, it is important to note that the effect of bigger tires on fuel efficiency can depend on various factors, such as the make and model of the vehicle, driving habits, and road conditions. For instance, larger tires with a more aggressive tread pattern might perform better on off-road or uneven surfaces but may cause a significant reduction in fuel economy on smooth pavement.

Generally, it is best to stick to the tire size recommended by the vehicle manufacturer to ensure optimal fuel efficiency(no fun!)….But a lot of us want to ride higher, be able to adventure further and explore everywhere. So bigger tires are needed! 

If you do choose to use bigger tires, it’s a good idea to consult with a mechanic or off road specialist (or just someone that has just recently done the tire upgrade on a similar vehicle) to understand how they might affect your vehicle’s performance and fuel economy.

How Much Mpg Will I Lose With Bigger Tires?

If you go up an inch or two you may see a decrease in mpg by 1 to 3 miles but it could be more depending on your vehicle. 

As soon as you start getting up to 3+ inches of tire size you may experience 5 to 10 drop in your mpg. 

Be sure to check if you need to regear your vehicle because that could make up a little bit of that drop. 

Also, understand that when you regear your vehicle for your bigger tires you probably won’t be going as fast on the highway!

What Is Rolling Resistance?

We talked about rolling resistance above so we wanted to explain it. 

Rolling resistance is a force that your engine needs to provide greater power than in order to move that tire, thus moving your vehicle. That force is made up of friction from the road, the weight of the tire, and the load of the vehicle. So when you have bigger tires your friction on the road goes up and the weight of the tire goes up causing your mpg to drop slightly. 

If you want to get deeper into it check out this write up from Schwalbe tires about rolling resistance.

Do Bigger Tires Affect MPG – Wrap up!

So yes bigger tires will affect your MPG but it will depend on how big you are going. If you are going up an inch or two then you might not see too much of a difference.

But if you want to be a beast on the trail and the highway then expect to spend more at the pump!!

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