Does Top Tier Fuel Actually Clean Your Engine? AAA Thinks It Has The Answer

Carbon deposits are a normal occurrence in an engine, but can build up over time, causing problems. Essentially, heat, pressure, and oxidation can transform unburned fuel into a black soot-like substance. This can gather around critical areas of the engine, like the injectors, intakes, and pistons. These deposits can compound over time, reducing performance efficiency, and eventually could lead to costly repairs. But you can save your engine with these tips for preventing and cleaning carbon buildup, which include choosing higher quality fuel.

Some major brands sell Top Tier fuel they claim can reduce existing carbon deposits in the engine. But does it actually work? AAA conducted a study back in 2016 putting this theory to the test. 

To be clear, all fuel has some additives, per EPA regulations, to help reduce the formation of carbon deposits. However, Top Tier fuel incorporates more detergents, above the minimum required. AAA concluded that drivers who switched from a product with the lowest allowable concentration of additives to Top Tier fuel may find a reduction of carbon deposits and “likely” would benefit more with extended use. 

But the AAA findings are largely based on testing performed on a single vehicle, which leaves plenty of room for speculation. So you’ll have to decide if it’s worth the extra three cents a gallon AAA said in 2019 it would cost to put Top Tier gas in your vehicle, at least until there’s a more thorough study.

Top Tier fuel was developed with the help of several automakers — including Mercedes-Benz, Audi, Ford, and General Motors — that wanted something above and beyond the EPA’s standard. While the specific mixture is different across suppliers, popular additives in Top Tier fuel include polyetheramines (PEAs), which are chemical compounds designed to dissolve carbon deposits in the engine. However, unlike some other additives, PEAs don’t break down as quickly in high temperature environments, like the one inside your engine.

Top Tier fuel isn’t a brand, and it doesn’t pertain to octane levels either, so you won’t need to select premium grade unless your car’s engine really needs it. Several gasoline brands offer Top Tier gas, and they must be licensed to carry it, along with maintaining certain performance standards. You can spot Top Tier fuel by looking for a sticker on the pump. To find stations in your area that carry it, use the search function on the Top Tier website, which lists all participating brands.