Top Tier gasoline is often dismissed as a marketing exercise, but a new AAA study says the benefits are real and car owners should be paying attention.
The American Automobile Association's Fuel Quality Research study has examined Top Tier gasoline's effectiveness. AAA relied on an independent testing lab to dig into both Top Tier and non-Top Tier gasoline.
Top Tier refers to gas with special detergent additives that promise to improve engine performance compared to other gas blends. It was created as a response to the EPA's mandate for a minimum level of gasoline detergent -- some automakers didn't think the minimum was enough to keep engines clean, and thus Top Tier was born.
After some 4,000 miles of simulated driving, testers found that non-Top Tier gas caused 19 times the carbon deposits in engines. This can have deleterious effects on engine performance, fuel economy and emissions.
"As advertised, tested Top Tier gasolines kept engines remarkably cleaner than other fuels we tested," said John Nielsen, AAA's director of engineering and repair. "By selecting a quality gasoline, drivers can minimize engine deposits, increase vehicle performance and improve fuel economy."
The study also measured consumer sentiment. While drivers acknowledged some benefit to Top Tier gas, most chose to stop at gas stations based on location and price, rather than gas quality. In fact, AAA's study found that just 12 percent of US drivers considered quality when choosing a gas station.
"Since Top Tier gasoline is widely available and only an average of 3 cents more per gallon, AAA urges drivers to reconsider their priorities when selecting a gas station," Nielsen said.