10 Best Engine Flush Cleaner of December 2025

• Easy way to clean and flush the oil systems of gasoline and diesel engines
• Gentle and rapid cleaning
• Neutral to seals and other materials installed in the engine
• Compatible with catalytic converters
• Simple to use

Liqui Moly

• Petroleum based formula does not contain kerosene or mineral spirits.
• Made in the USA
• Will not cause leaks, plug ports, galleys or screens; for all domestic and import gasoline engines.

Golden Touch

• Quickly and safely cleans harmful sludge and other deposits in the crankcase immediately before an oil and filter change
• Safe for Diesel engines
• Detergents and dispersing gently clean and suspend sludge deposits. Opens restricted oil passages to improve overall oil circulation.
• Does not contain aggressive solvents (Acetone, toluene, xylene)
• Removes water for enhanced corrosion resistance
• Fit Type: Universal Fit

Berryman Products

• STP Super Concentrated High Mileage Engine Flush cleans and prepares your vehicle's engine for new oil
• STP High Mileage Oil Treatment + Stop Leak's high-viscosity formula, complete with anti wear agent ZDDP, is specially formulated to help fight metal-to-metal friction by providing a thicker cushion between moving engine parts
• STP High Mileage Transmission Stop Slip + Leak Repair is scientifically engineered with Anti-Wear additives and with antioxidants to help stabilize transmission fluid; formulated to help recondition and protect transmission seals, eliminate slip and reduce rough shifting
• STP Ultra 5-in-1 Fuel System Cleaner contains high-performance detergents and friction modifiers that come together to form a one-source solution to help to save gas by deep cleaning the entire fuel system, restore peak performance, reduce friction, prevent ethanol deposits and inhibit corrosion

STP

• Recommended for use in all gasoline and diesel engines, including all turbo-charged engines
• Safe for use in engines that use conventional or synthetic motor oil
• Removes accumulated gum, varnish and sludge from internal engine parts
• Releases sticky valves and piston rings
• Allows oil to circulate freely to all parts of the motor

Niteo

• 2-in-1 formula designed for light flushing and heavy-duty cleaning
• Cleans cooling systems to help prevent overheating
• Non-toxic, non-acidic formula is easy-to-use and safe for all cooling system metals
• Effectively removes heavy deposits by drawing metal oxides into the solution
• Strong enough to help restore maximum cooling system efficiency

Prestone

• Use before changing oil in gas or diesel engines
• No harmful solvents to damage seals or gaskets
• Safely remove accumulated amounts of varnish, sludge and by-products of combustion
• Premium synthetic blend that contains special detergents and dispersants
• Prepares engine for fresh oil

Lubegard

• Cleans and protects anything exposed to salt (saltwater, salt air, road salt)
• Dissolves salt and leaves a protective coating to inhibit corrosion
• Essential as a motor flush for marine engines in both saltwater and freshwater environments
• Biodegradable formula
• Size: 1 Gallon
• Salt Terminator dissolves salt and leaves a protective sheen, guarding against future salt corrosion
• 1 Gallon (128 oz) Concentrate only, great for when you already have the mixer
• Spray on any surface exposed to saltwater or salt air to clean and protect from corrosion
• Connect to your engine's flushing unit to add years of service to outboards, I/Os, and PWCs
• This is an ideal product for rinsing trailered boats, PWC, dive gear, fishing gear, or anything that comes into contact with corrosive salt

CRC

• Safely and carefully cleans engine oil system from all kinds of contaminations, ensures its technical purity
• Removes carbon and restores mobility of stuck piston rings.
• Universal for all engine types including turbo-supercharged ones.
• Due to revitalizant provides creation of engine protection reserve.
• Cleans crankcase ventilation system. Eliminates effect of hydraulic lash adjusters sealing

XADO

• Frees valves and lifters
• Reduces friction and wear
• Maintains oil viscosity
• Cleans and conditions engines
• Dissolves and removes harmful deposits

Rislone