Going above 60 miles per hour lowers your gas mileage. For every five miles per hour above 60 you drive, you're paying roughly an extra 20 cents per gallon of gas.

Even though you think the cops won't pull you over, don't push 90 miles per hour on the highway. Try going closer to the speed limit and you'll save gas and money.

If every driver who hit the stretch between Los Angeles and Las Vegas drove the speed limit for one year, the money saved would equal $76 million dollars. That's enough to buy 768 Tesla Roadsters-the highly anticipated fully-electric sports car with a long waiting list.

Department of Energy
FuelEconomy.gov