When it comes to fuel economy, every driver wants to maximize their mileage and spend less money at the pump. Although fuel efficiency varies from vehicle to vehicle, there’s a simple factor that affects everyone equally: tire pressure. Here’s what you should know about the relationship between tire pressure and fuel economy, as well as some essential tips that will keep your tires at their optimal pressure.

The Impact of Tire Pressure on Fuel Economy

In a study conducted by Oak Ridge National Laboratory, researchers tested a 2009 Toyota Corolla at different tire pressures, ranging from the recommended pressure to 75% and 50% of the recommendation. They consistently found that fuel economy decreased by 2-3% when the tires were at 75% of the recommended pressure. However, the fuel economy was even worse at 50% pressure when driving at speeds of 40 miles per hour or less—about 10% lower than properly inflated tires.

Proper air pressure plays a crucial role in reducing tire resistance and improving fuel economy. When your tires are underinflated, the rubber becomes loose and soft, which increases rolling resistance on the road. This forces your engine to work harder, which in turn burns more fuel and costs more money at the pump. Even worse, underinflated tires pose safety risks because they can contribute to longer stopping distances, poor handling, and potentially dangerous blowouts.

According to the U.S. Department of Energy, keeping your tires at the recommended pressure can enhance gas mileage by up to 3%. To put this into perspective, if you buy gas at $4.00 per gallon, you could save $2.40 per fill-up on a 20-gallon tank. Over the course of a year, that’s almost $125 in savings! While that may not seem like a lot, it adds up over time.

Tips for Maintaining Proper Tire Pressure

As you can see, maintaining the proper air pressure in your tires helps you stay safe and saves money. Here are a few practical tips to help you keep your tires at optimal levels:

  • Keep Your Tires Inflated: Refer to the sticker in your car’s driver-side door jamb or your owner’s manual for the recommended tire pressure. Use a tire gauge to measure the PSI (pounds per square inch) of each tire and adjust the air pressure as needed. Many gas stations offer air to inflate your tires if you don’t have a pump of your own. While the Tire Pressure Monitoring System (TPMS) is a handy feature, don’t rely on it for regular air pressure maintenance. By the time the TPMS light comes on, at least one of your tires is already severely underinflated and should be filled immediately.
  • Rotate Your Tires Regularly: To keep your tires wearing evenly and prolong their life, it’s important to rotate your tires approximately twice a year or as recommended in your owner’s manual. A good rule of thumb is every 5,000 miles for best results.
  • Have Wheel Alignments Performed Regularly: Proper wheel alignment reduces tire wear and keeps your vehicle traveling straight without pulling to one side. Correct alignment decreases rolling resistance and improves fuel economy. Be sure to schedule regular alignments to maintain optimal performance and safety.
  • Replace Your Tires When Needed: Regardless of how well you take care of your tires, the tread will eventually wear down. When this happens, it affects your fuel economy and traction. To determine if it’s time for a replacement, perform the penny test. With Lincoln’s head facing down, insert a penny into the shallowest part of the tread; if the tread doesn’t reach the top of Lincoln’s head, it’s time for new tires.

It’s also important to understand that tires naturally lose about 3.5 psi of pressure over a year due to their porous nature; climate conditions can also affect tire pressure. In colder weather, tires are more likely to be underinflated because the cooler temperatures causes the air to contract; during hot weather, tires may become overinflated because the heat causes the air to expand. For this reason, it’s always recommended to check your tire pressure more often when there are significant decreases or increases in outdoor air temperature.  

Still Experiencing Fuel Efficiency Issues?

Maintaining proper tire pressure is essential for maximizing your fuel economy and your safety on the road. However, if you’ve followed the above tips and still seem to have issues with decreased fuel efficiency, you may be dealing with a different issue. There are a number of things that can affect fuel efficiency, including dirty or faulty fuel injectors, clogged air filters, bad spark plugs or spark plug cables, the wrong oil in your engine, and even your driving habits.

Whether you need a wheel alignment or wish to determine the cause of poor fuel economy, you can always rely on the team at Express Auto/RV Care Center! Located in the Foothills in Yuma AZ, we’re a third-generation family-owned auto repair shop accredited by the Better Business Bureau. We offer comprehensive same-day service for most makes and models and provide a 3-year/36,000-mile warranty on all repairs—plus a satisfaction guarantee! Contact us today at (928) 305-0767 or request an appointment online.

Want more great advice on saving money on car repairs? Order Russell McCloud’s book Knowledge is Power by clicking here.