Drive Smart

Keep your tires inflated to the right pressure.

The U.S. Environmental Protection Agency and Department of Energy estimate that gas mileage would improve by 3.3% if we kept our tires inflated to the pressure recommended by car manufacturers. That’s because a car engine must work harder—and thus use more fuel—to overcome the additional rolling resistance created by under-inflated tires when the rubber meets the road.

Each time we burn one less gallon of gas, we save 20 pounds of carbon dioxide pollution from being released into the atmosphere. In 2005, American drivers bought 138.7 billion gallons of gas.

By inflating our tires properly, that 3.3% fuel efficiency improvement would have saved in just one year:

  • 4.6 billion gallons of gas
  • $13.7 billion (at $3/gallon)
  • 45.8 million tons of carbon dioxide pollution

Here’s how it works.

Let’s say you own a typical car in Illinois that gets 20.8 miles per gallon. The Illinois Department of Transportation says average Illinois drivers puts 15,000 miles on their cars each year and thus use 721 gallons of gas per year.

Keeping your tires inflated will save:

  • 23 gallons of gas
  • $69
  • 460 pounds of carbon dioxide pollution

What will it cost you to do this? Almost nothing. First, check your owner’s manual to learn where the recommended tire pressure is posted on your vehicle. Then, the next time you get your oil changed, ask your mechanic to check your tires and fill them if needed.

If you want to check the pressure yourself, spend about $20-$25 for a high-quality dial-type or digital gauge. They’re more accurate, but more expensive, than the popular pencil-type gauges that sell for about $5.

One last tip

Be sure to check your tires when they’re cold–you’ll get a more accurate pressure reading.