New testing from AAA has uncovered significant differences in the quality of gasoline sold at fuel retailers in the United States.

 The independent laboratory testing compared gasolines that meet TOP TIER™ standards, often marketed to consumers as having enhanced engine-cleaning detergent additives, with gasoline brands that do not participate in the automaker-backed program.

 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.

 To protect vehicle investments, AAA urges drivers to use a gasoline that meets TOP TIER standards for engine cleanliness and performance.

In response to increasing levels of carbon deposits in modern engine designs, the Environmental Protection Agency mandated a minimum level of detergent for all gasoline sold in the U.S. in 1996. However, some automakers believe the minimum does not go far enough to ensure optimal vehicle performance and their ability to meet increasingly-stringent fuel economy and emissions requirements. The TOP TIER program and performance standard were developed to guarantee that program participants’ gasoline meets stricter targets for engine cleanliness.

To ensure a gas station sells a high quality gasoline, consumers should research the fuel options near them.