The study of the American Automobile Association (AAA) discovered that when it comes to the good condition of a car's engine, not all gasoline is created equal.

The North America's largest motoring and leisure travel organization's new testing found out the significant differences in the quality of gasoline sold at fuel retailers in the United States. The American Automobile Association recommends that drivers should pay extra attention to protect their vehicle investments, according to Tulsa World.

The American Automobile Association's laboratory testing compared gasoline brands that fulfill Top Tier standards with brands that do not take part in the automaker-backed program for the highest cleanliness standard for gasoline performance.

John Nielsen, AAA managing director of automotive engineering and repair, said in a statement that by making the practical use of the Top Tier fuel, drivers tend to minimize engine deposits,  improve fuel economy as well as boost vehicle performance.

Nielsen also said that the association was surprised to learn the extent to which detergent additives impact gasoline quality. And the top brands remarkably maintained the engines cleaner compared to other fuels they tested, CNN reported.

While the gasolines which are not Top Tier caused 19 times more engine deposits rather than Top Tier brands after just 4,000 miles of simulated driving. In that, carbon deposits are known to increase emissions, negatively impact vehicle performance and reduce fuel economy.

Beth Mosher, spokeswoman of the American Automobile Association, said that Top Tier refers to different brands of gas and is not to be confused with various grades such as, mid-grade, premium and unleaded, based on the report of Daily Herald.

The top tier gasoline brands that passed the AAA's test includes: Exxon Mobil, Conoco, BP, Shell, Chevron, Citgo, as well as Valero and Phillips 66 (PSX).

Tulsa Tech's Broken Arrow Campus' transportation program coordinator - Adam Ellis, stated that Top Tier fuel is better for vehicles.