ATLANTA — When you’re deciding where to pull over for gas, do you look for the Top Tier logo? Maybe you should start!

Engine-cleaning detergent additives in gasoline really do make a difference and are worth the extra price to keep your car healthy, according to independent laboratory testing from AAA.

Several Georgia gas stations have sold customers contaminated gasoline in recent years. We're looking at what the state is doing to safeguard Georgia's fuel supply, Monday at 5 p.m.

The group’s researchers found “significant” differences in the quality of gasoline sold across the country.

AAA: Why you should fill up with Top Tier gas

Since the 1990s, the Environmental Protection Agency has required a minimum level of detergent for all gas sold, but some automakers believe the EPA standards aren’t good enough.

To be considered Top Tier, the gasoline must have a higher concentration of detergent added to it.

AAA said it was surprised that detergent additives made such an impact on gasoline quality. The group is now urging drivers to use a gasoline that meets Top Tier standards for engine cleanliness and performance.

"Among brands tested, non-Top Tier gasolines caused 19 times more engine deposits than Top Tier brands after just 4,000 miles of simulated driving. Such carbon deposits are known to reduce fuel economy, increase emissions and negatively impact vehicle performance, particularly on newer vehicles."

Every service station that sells Top Tier fuel must add the detergent package to all grades of gasoline.

According to AAA, Top Tier gasoline costs an average of three cents more per gallon, but money expert Clark Howard says it doesn’t have to be more expensive.

“The most important thing about the report is that many of the nation’s giants of gas discounting sell Top Tier gasoline, including Costco and QuikTrip,” Clark said. “There are many who decide to buy gas only at major oil company stations believing their gas to be superior. However, you can have what the study finds is the best gas at the lowest prices.”

Where do you find Top Tier fuel options? They’re all over! According to Top Tier, about a third of gas stations meet its fuel quality standards.

Here are the Top Tier licensed retail brands, as of April 2018:

76
Aloha
Amoco
ARCO
Beacon
BP
Break Time
Cenex
Chevron
Chevron (El Salvador)
Chevron (Guatemala)
Chevron (Honduras)
Chevron (Panama)
CITGO
Conoco
Co-op
Co-op Premium Diesel (select locations only)
Costco Wholesale
Costco Wholesale – Diesel (select locations only)
CountryMark
CountryMark PLUS
Diamond Shamrock
Esso
Express Mart
Exxon
Fast Fuel
Fast Stop – Diesel (select locations only)
Fast Stop Express – Diesel (select locations only)
Hele
HFN – Hawaii Fueling Network
Holiday
Irving Oil
Kirkland Signature Gasoline
Kirkland Signature – Diesel (select locations only)
Kwik Star
Kwik Trip
Kwik Trip Express
Mahalo
Marathon
Metro Petro
MFA Oil
Mobil
Mobil (Canada)
OAAI
Ohana Fuels
Petro-Canada
Phillips 66
PUMA (El Salvador)
PUMA (Panama)
PUMA (Puerto Rico)
QT
QuikTrip
Ranger
Ranger Mustang
Ranger Stallion
Ranger Thoroughbred
Reeder's
Shamrock
Shell
Shell (Canada)
Shell (Puerto Rico)
Sinclair
Sunoco
SuperAmerica
SuperFuels
Tempo (Canada)
Texaco
Texaco (El Salvador)
Texaco (Guatemala)
Texaco (Honduras)
Texaco (Panama)
Tri-Par Qwik Stop
Valero
Win Win

Don’t see your gas station on this list? Check for the Top Tier logo on display at the service station or ask an employee.

If you haven’t been using high quality gasoline, it’s not too late to start. AAA says you can reverse some of the damage by making the switch to Top Tier gasoline.

Cox Media Group