TAMPA, Fla. (WFLA) — A recent independent study by AAA finds that the quality of gas can make a difference in drivability and gas mileage.
Top Tier gasoline can improve gas mileage. Top Tier gas is a particular type of gasoline that contains detergents. This is not be confused with the “grade” of fuel such as the level of octane in the gas. All gas stations that sell Top Tier gasoline must have the detergents in all fuel grades.
Over time, engine deposits develop on intake valves which can restrict airflow. The detergents in Top Tier gasoline reportedly clean those deposits. AAA found that after running a vehicle for 4,000 miles the vehicles using Top Tier gas had 19 times fewer deposits than vehicles not using Top Tier gas. AAA reports vehicles also increased their gas mileage by 2-to-4 percent.
However, Lee Williams, the service manager at Engine Lab, explains if a vehicle has a direct injection engine, the Top Tier gas won’t make a difference. This is because the detergents bypass the valves and are not able to clean the carbon deposits on them.
AAA also reports gas at Top Tier stations usually cost about three cents more per gallon than non-Top Tier stations. Using non-Top Tier gas is not bad for your vehicle, however, you could see increased performance with Top Tier gas.