Unless your engine is designed to run on premium gasoline-which is usually just the case for high-performance vehicles-buying high-octane fuel is a waste of money, and actually ... read full tip

Unless your engine is designed to run on premium gasoline-which is usually just the case for high-performance vehicles-buying high-octane fuel is a waste of money, and actually increases pollution. Running your engine on high-octane fuel unnecessarily yields no benefits in terms of performance, cleanliness, or fuel economy. In fact, gas mileage decreases as octane increases.

So check your owner's manual. If you're pumping premium fuel into a car meant to run on regular unleaded, you could save at least 20 cents per gallon by switching grades. After a year, you will have saved $115.

Americans use 13 billion gallons of premium grade gasoline per year. If just 10 percent of this consumption were redirected to regular unleaded gas, these better-informed drivers could save a total of $275 million annually-enough to provide free gas to 180,000 drivers for an entire year.

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