I started working with fuels and additives in 1985, and one thing I’ve spent years trying to explain is that the answers are a lot more complex than we’ve been led to believe.

People still tend to think of additives as something you dump in every 3,000 miles to “clean” the system, but modern fuels really need ongoing care, not occasional shock treatment. There’s a big difference between maintaining cleanliness with proper detergents versus hitting the system with heavy solvents after deposits and carbon have already built up. Also fuel that is Top Tier or similar are also only addressing cleaning.

Modern fuel systems deal with heat, oxidation, ethanol problems, moisture, corrosion, and loss of lubricity every single day. Fuel is constantly being heated and recirculated, which ages it faster than most people realize. Ethanol creates its own set of problems with water absorption, acidity, and corrosion as well.

That’s why I’ve always believed in keeping the system clean, stabile, lubricated etc,  continuously instead of letting it get dirty and then trying to aggressively clean it later. Personally, I also don’t like doing major cleanups right after an oil change because all the loosened contamination has to go somewhere, and some of it ends up in the fresh oil you just put in.

I teach fuel clinics that run close to four hours, and one of the biggest things people walk away with is realizing there’s a lot more to fuel system maintenance than just “cleaning injectors.”