See how AMSOIL products perform in the lab and in the field.

Consumers have the freedom to choose other than OEM branded lubricants without fear of voiding the original limited or implied warranty. Amsoil synthetic lubricants and performance products are tough, reliable, long lasting, and save you time and money with the peace of mind that your vehicles/ equipment will last longer. About Warranty Secure

Marine & Personal Watercraft

The use of oil designed for marine engines is critical, yet less than 50% of owners use a product dedicated to marine applications, for both sterndrive and inboard engines. Out-Board owners are better at 80% choosing the correct injector or premix oils for marine use. Greater amounts of rust and corrosion inhibitors are added to marine oils which are not found in regular motor oil for automobiles or injector oils without a 2- stroke watercraft (TC-W) rating. Because marine engines are not used on a daily basis and with the natural humid environment, additional corrosion additives are critical for marine engines.

Marine engines are constantly under load, which can shear the molecular structure of oil and reduce its ability to guard against wear. Typical inboard marine engine will run about 5000rpm at 30 mph compared to an automobile that runs at about 2000rpm at 60mph unlike your auto that eases its load with coasting to stops or downhill travel… boat motor rarely coast. AMSOIL formulates its inboard marine oils to withstand these operating requirement so you can spend more time fishing and boating with all the horsepower your engine was designed to deliver.

AMSOIL synthetic marine lubricants are engineered with advanced technology to protect marine two- and four-stroke engines and stern drives from water contamination to give you reliable, performance and peace of mind on the water. From high-speed power boats to idle rides around the lake and from Jet Ski to yacht diesel marine engines, AMSOIL synthetic marine lubricants are formulated to keep two- and four-stroke engines operating at peak efficiency, so you can enjoy your time on the water safely.

Our customers ask: “Is it OK to break in new two-stroke equipment using AMSOIL synthetic motor oils?
AMSOIL Technical: “Yes. There are no problems using AMSOIL synthetic two-stroke oils for break-in periods.”

Our customers ask: “Can I use AMSOIL HP Marine Synthetic 2-Stroke Oil in my Evinrude® E-TEC™ at the factory-lean setting?”
AMSOIL Technical: “Yes. HP Marine is excellent for Evinrude® E-TEC™ factory-lean setting (replaces Evinrude XD100™ 2-Cycle Oil).”

“HP Marine oil can be used in all two-stroke marine engines that specify TC-W3, including those made by: Johnson/Evinrude, FICHT, E-TEC, Mercury EFI & Optimax, Yamaha, Nissan, Tohatsu TLDI*, Suzuki, Mariner, Force.”
(Use as injection oil or 50:1 premix.)

Our customers ask: “My Mercury owner’s manual specifies a synthetic-blend, which AMSOIL products should I use?
AMSOIL Technical: “Mercury’s owner’s manual discourage the use of full-synthetic and most owners will not consider straying from these guidelines. So AMSOIL designed a product for these customers known as “WCM” Marine synthetic-blend Engine Oil SAE 25W-40.


Why River Resort & Outfitting Trust Amsoil for rental boats for less maintenance/ reliability and low toxicity (no engine smoke and residual oil film on the water)

Synthetic 2-Stroke Marine Oils

Excels in normal and lean factory settings. Maximizes engine life. Low aquatic toxicity
Protects against rust and wear. Controls engine deposits. Ideal for direct-injection outboard motors
Improves throttle response. Delivers smokeless operation. Premium protection at 100:1 mix ratio
Excellent high-stress, high-rpm endurance. Increased rust and corrosion protection. Designed specifically as a “synthetic –blend” to meet Mercury & MerCruiser owner’s manual specification

Synthetic 4-Stroke Marine Oils

Excels in high-horsepower applications. NMMA FC-W Catalyst Compatible. Provides excellent mechanical stability
Excels in high-horsepower applications. NMMA FC-W Catalyst Compatible. Provides excellent mechanical stability

Synthetic Diesel Marine Oil

Helps control soot thickening, oxidation & wear. Maximum fuel economy. Protects for up to 3X manufacturer-recommended drain interval


Great for boat trailer wheel bearings

Marine Gear Lube

Protects components, even when contaminated with 10% water. Reduces friction and wear. Helps prevent rust and corrosion

Gasoline Fuel Additives and Carburetor Cleaner

Increases octane up to 3 numbers. Improves startup performance. Designed to increase power
Cleans fuel systems. Addresses ethanol-related performance issues. Stabilizes fuel.
Helps keep fuel from deteriorating. Protects against varnish and gum buildup. Helps keep engines running at peak performance.
Cleans combustion intake systems. Helps restore stability and engine smoothness. Maximizes mpg and hp

Diesel Fuel Additives

Removes deposits in all types of diesel engines. Lubricates fuel-pump and injectors to prevent wear. Improves fuel economy
Maximizes horsepower. Helps increase fuel economy. Improves start-ability

Spray Lubricants and Cleaners

Lubricates and protects nonmetal surfaces. Locks-out moisture. Will not attract dust or dirt
Disperses water. Protects metal surfaces. Penetrates existing rust build-up
Contains additives that specifically protect against corrosion. Displaces water and seals equipment from water intrusion. Leaves a dry, long-lasting (up to several years), wax-like amber film
Loosens grease and grime. Fast-acting. Leaves a clean scent
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