Should you care how much detergent is in the gasoline you buy? How can you even tell?
Leading  automakers BMW, General Motors, Honda, Toyota and Volkswagen think you  should care, and they want to help you find stations that sell the  cleanest gas. They want some fuels certified as best for fuel economy  and emissions. Not everybody’s on board, though.
The automakers  formed a consortium, Top Tier Gasoline, that certifies retailers as  meeting their standard for detergent. Detergents prevent deposits of  leftover material from building up in engines and exhaust systems. The  deposits, like the crust of minerals left when hard water evaporates,can  reduce fuel economy and performance.
Read Article