There are a number things you can do to increase gas mileage in your cars.

The U.S. Department of Energy says the simplest thing is to slow down. The Energy department says most cars reach their peak

efficiency cruising at a steady 55 to 60 mph.

Every 5 mph over that will cost about 21 cents per gallon.

So if you pay $2.50 for a gallon of gasoline, and then drive 65 mph it's as if you paid $2.71 per gallon.

If you drive 70 mph, it's as if you paid $2.92 per gallon.

Another gas saving tip is to remove excess weight. An extra 100 pounds could reduce the miles per gallon by 2 percent. That's equivalent to five cents a gallon.

Also, you should avoid excess idling, which gets zero mpg. Cars with larger engines waste more gasoline than smaller engines while idling.

Using cruise control if you have it also saves because it prevents the driver from speeding up and slowing down.

Drivers also need to keep tires properly inflated; it can save you 3 percent, or about 8 cents per gallon.

Other tips that help in the long term:

Keep your car tuned. It can save up to 4 percent of gasoline usage, or 10 cents per gallon.

Replace dirty air filters, which could cost you 10 percent of your gasoline.