Lucas Complete Engine Treatment Cleaner & Lubricator (16 oz)

Stubborn carbon deposits and varnish buildup can quietly rob your engine of performance over time. Lucas Complete Engine Treatment works two ways depending on how you use it — add it to your fuel tank to clean everything from the tank to the cylinders, or pour it in with your oil to reduce heat and friction throughout the engine.

What makes this 16-ounce treatment versatile is that it handles both sides of the equation. In the fuel system, it dissolves deposits, fights corrosion, and helps fuel burn more completely. On the oil side, it forms a protective barrier that improves oil flow during cold starts and can extend the life of your oil between changes. The formula is compatible with all engine types, all fuel grades, and all oil weights — gasoline, diesel, synthetic, or conventional.

A single bottle treats one oil change or one tank of fuel. For ongoing maintenance, many owners add it at every oil change or every few fill-ups to keep things running clean.