Whether you drive an economy car, an SUV or a sports car, chances are your vehicle represents one of the largest purchases you will make in your lifetime. Yet many drivers don't give a second thought to the type of gasoline they put in their tanks, even though using the right type of fuel is an important aspect of overall car care.

To help you make an informed decision the next time you pull up to the pump, take the following quiz to help separate fuel fact from fiction:

1. Fact or fiction? It doesn't matter what brand of gasoline you use in your vehicle, because all gasoline is about the same.

2. Fact or fiction? All gasoline contains additives, but that may not be enough to keep an engine clean and working properly.

3. Fact or fiction? The only cars that benefit from premium gasoline are high-performance and luxury vehicles.

4. Fact or fiction? Your driving habits and where you live can affect the grade of gasoline you should use in your vehicle.

Answers:

1. Fiction - All gasolines are not the same. Gasoline is composed of two primary components - the base fuel and the additive. On a regional basis, the base fuel may be similar among brands, but the additive typically is different. According to several automakers, additives with more-sophisticated and higher levels of cleaning agents can help protect vehicle engines from harmful carbon deposits that are known to decrease engine performance.

2. Fact - While all gasolines should contain enough detergent to meet minimum government standards, not all automakers believe the minimum detergent standard is adequate. BMW, Honda, General Motors and Toyota recommend filling up with gasoline that meets the Top Tier detergent standard. This new standard requires detergent above the minimum government standard. For example, all Shell fuels meet the Top Tier standard.

3. Fiction - Though high-performance engines generally require premium gasoline, there are many exceptions. Different cars may require different levels of octane - the measure of a gasoline's ability to resist engine knock (the rattling or pinging sound that results from uncontrolled combustion in the engine). Whether you drive a luxury sedan or an old truck, the right level of octane should help prevent engine knock and help ensure optimal performance. To determine the appropriate octane level or grade of gasoline for your vehicle, check your owner's manual.

4. Fact - According to the American Petroleum Institute, several factors can affect how gasoline performs in your engine, including driving habits, the amount of miles on the vehicle's odometer, climate and geography. For example, if your engine knocks slightly during everyday driving but now you're hauling heavy loads, you may want to choose a higher-octane grade of gasoline. In addition, octane requirements are generally lower in higher altitudes. So if you live in a mountainous region, the octane level of the gasoline in your area has been adjusted for the altitude difference.