When your engine runs at peak efficiency, it reduces pollution. Cars and trucks account for nearly one-fifth of all US emissions, emitting twenty-four pounds of global-warming gases per gallon of gas. Nineteen of those pounds come right out of your car’s tailpipe.

Service your vehicle. Good maintenance increases fuel efficiency.

You can also improve your gas mileage by 0.6% on average—up to 3% in some cases—by keeping your tires inflated to the proper pressure. Underinflated tires can lower gas mileage by about 0.2% for every 1 psi drop in the average pressure of all tires. Properly inflated tires are safer and last longer.

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