“Top Tier” refers to gasoline with detergent additives that meet specific engine cleaning standards established by a coalition of automakers years ago, because the automakers felt the standards set by the EPA weren’t good enough.
AAA’s independent laboratory testing compared Top Tier gas with brands that do not meet the Top Tier standards and found that the non-Top Tier gasolines caused 19 times more engine deposits after just 4,000 miles of simulated driving.
Such deposits are known to reduce fuel economy, increase emissions and negatively impact vehicle performance, particularly on newer vehicles, according to the report.
“AAA was surprised to learn the extent to which detergent additives impact gasoline quality,” John Nielsen, AAA’s managing director of Automotive Engineering and Repair, said in the release. “As advertised, tested TOP TIER gasolines kept engines remarkably cleaner than other fuels we tested.”
AAA research found that motorists who switch to a Top Tier brand can reverse the effects of the non-Top Tier gas after just a few thousand miles. Performance issues like rough idling or hesitation during acceleration can often be resolved.
Despite the fact that two-thirds of U.S. drivers believe there is a difference in quality of gasoline sold by different gas stations, a AAA survey reveals that Americans value convenience and price over quality when it comes to selecting a gas station.
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