AMSOIL Shipping Information
Online StoreAMSOIL Preferred Customer ProgramAMSOIL Business AccountsAMSOIL Dealership OpportunityOrder FREE AMSOIL Product CatalogContact Us
Email Price List

10W-40 Synthetic Formula 4-Stroke Marine Oil (WCF)

 10W-40 Synthetic Formula 4-Stroke Marine Oil (WCF)
Product Code: WCF • Brand: AMSOIL

For use in 4-stroke gasoline fueled engines in marine applications. Offers unsurpassed wear protection, viscosity stability, low volatility and excellent rust protection. NMMA FC-W approved and "warranty certified". For use in 4-stroke outboard and marine inboard engines. Also excellent for personal watercraft.

Package sizes include:

1-Quart Bottle
1-Quart Bottles (case of 12)
55-Gallon Drum

See Pricing or Place an Order
MSDSData Sheet

Product Details

Product Applications

AMSOIL Formula 4-Stroke® Marine Synthetic 10W-40 Motor Oil (WCF) is recommended for gasoline fueled four-stroke outboard, inboard, inboard/outboard (I/O) and personal watercraft motors. AMSOIL WCF motor oil is recommended for the following applications whenever an SAE 10W-40, 15W-40, 25W-40 or straight SAE 40 oil is called for:

Four-stroke outboard motors: Honda®, Mercury®, Yamaha®, Johnson®/Evinrude®, Bombardier/BRP®, Suzuki®, Nissan®, Tohatsu®, OMC®, Volvo Penta®, Mercruiser®, Chevrolet®, Ford®

Inboard and I/O: Mercruiser®, Volvo Penta®, OMC®, Chrysler® Marine, Crusader®, Marine Power®, Chevrolet®, Ford®

Personal Watercraft: Honda®, Yamaha®, Bombardier/BRP® (Sea-Doo®), Polaris®

Note: AMSOIL Formula 4-Stroke® Marine Synthetic 10W-40 is recommended for use in place of 25W-40 as specified by Mercury®.

NMMA FC-W Catalyst Compatible • API SM

Product Description

AMSOIL Formula 4-Stroke® Marine Synthetic Motor Oil is a premium-quality synthetic formulation engineered for the harsh operating conditions of marine environments. It withstands the intense mechanical action of continuous, high-rpm operation to deliver superior viscosity protection. Formula 4-Stroke Marine Synthetic Motor Oil is specially fortified with a heavy treatment of advanced additives that protect

4-Stroke Outboard Motor Warranty Certified

Formula 4-Stroke® Marine Synthetic Motor Oil is certified by the National Marine Manufacturers Association (NMMA) for use in four-stroke outboard motors. This high quality oil demonstrates outstanding performance, exceeding the NMMA "FC-W" (Four Cycle-Water) specification requirements. Formula 4-Stroke® Marine Synthetic Motor Oil fulfills the warranty requirements of four-stroke outboard motor manufacturers.

• NMMA Registration #FB-30010B 10W-40

Superior Protection Against Engine Wear

Marine engines operate under high loads and RPMs for extended periods of time, causing traditional automotive oils to break down and lose viscosity. To ensure good protection, the NMMA set minimum shear stability requirements for FC-W. AMSOIL Formula 4-Stroke® Marine Synthetic Motor Oil greatly exceeds the FC-W shear stability requirements, outperforming competitive oils to deliver a superior lubricating film. Formula 4-Stroke® Synthetic Oil also contains robust anti-wear additives that further reduce wear in metal-to-metal contact regions (see Four-Ball Wear Test graph).

4 ball Test

HTHS Viscosity

While automobile engines normally operate at around 2,500 rpm, outboard motors can run twice as fast, requiring greater levels of wear protection and better bearing durability than automobiles. In addition, prolonged idling and low operating temperatures contribute to fuel dilution, further thinning the oil. To ensure adequate protection for their engines, marine engine manufacturers set minimum high temperature/high shear (HTHS) viscosity limits. AMSOIL Formula 4-Stroke® Marine Synthetic Motor Oils are shear stable and formulated with sophisticated oil additive chemistry, exceeding the HTHS requirements of both the API and NMMA FC-W (see graph).

HTHS Viscosity

Excellent Anti-Rust Performance

Marine engines are prone to rust, leading to uncontrolled wear and premature engine failure. However, good rust protection is not natural to engine oil. It comes only by design. Formula 4-Stroke® Marine Synthetic Motor Oil is fortified with a special anti-rust agent, even more than required to pass stringent NMMA FC-W anti-rust testing.

Service Life

Four-stroke outboard motors and personal watercraft applications: Due to potential fuel dilution or water contamination, change oil at the engine or watercraft manufacturer recommended interval.

Inboard and I/O applications: Change oil at two times the engine manufacturer recommended interval or one year, whichever comes first.

Mixing AMSOIL

AMSOIL Formula 4-Stroke® Marine Synthetic Motor Oil is compatible with conventional and synthetic motor oils. Mixing AMSOIL motor oils with other oils will, however, shorten the oil life expectancy and reduce the performance benefits. AMSOIL does not support extended drain intervals where oils have been mixed.

Aftermarket oil additives are not recommended for use with AMSOIL motor oils.

HEALTH & SAFETY

This product is not expected to cause health concerns when used for the intended application and according to the recommendations in the Material Safety Data Sheet (MSDS).

Click here to view the MSDS Data Sheet for AMSOIL WCF.

Keep out of the reach of children. Don't pollute. Return used oil to collection centers.

Technical Data

TYPICAL TECHNICAL PROPERTIES
AMSOIL FORMULA 4-STROKE® MARINE SYNTHETIC MOTOR OIL (WCF)
SAE 10W-40
Kinematic Viscosity @ 100°C, cSt (ASTM D445)14.1
Kinematic Viscosity @ 40°C, cSt (ASTM D445)93.3
Viscosity Index (ASTM D2270)155
Pour Point °C (°F) (ASTM D97) -38 (-36)
Flash Point °C (°F) (ASTM D92)240 (464)
High-Temperature/High-Shear Viscosity (ASTM D5481)4.2
Four Ball Wear Test (ASTM D4172 @ 40 kgf, 150°C, 1800 rpm, 1 hour, Scar in mm) 0.40
Noack Volatility, % weight loss (g/100g) (ASTM D5800)7.5
Total Base Number (ASTM D2896)7.9

Related Videos

AMSOIL Marine Oils are put to test in Evinrude E-Tec equipped rental boats


 10W-40 Synthetic Formula 4-Stroke Marine Oil (WCF)

Did this product meet your expectations?

(click on a star to vote)

Product Name: Four Stroke Marine Motor Oils (WCF,WCT)
Current Rating: 4.88out of 5 stars
Votes & Reviews: 45 vote(s) and 49 user reviews.


A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Norman: space

My first boat. Amsoil is my only choice.

This is my first boat. It has a Yamaha 175hp SHO 4-Stroke. I have Amsoil in everything I own. After the breakin hours passed. I replaced everything with Amsoil. Motor,lower unit and bearing grease. It's the only oil for me. Always a Great choice.

Item Reviewed: Four Stroke Marine Motor Oils (WCF,WCT)
Discussion Url

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by James: space

I buy this marine-specific synthetic oil.

I use this great lube oil for my 1990 Cruisers Esprit with twin Crusader 350's. I am never disappointed with this synthetic, even though they were designed for straight SAE 40. They run smooth and oil pressures are spot on.

Item Reviewed: Four Stroke Marine Motor Oils (WCF,WCT)
Discussion Url

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Robert: space

The best oil I've used so fat

Fantastic no issues with this product will buy again and recommend it

Thanks

Item Reviewed: Four Stroke Marine Motor Oils (WCF,WCT)
Discussion Url

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Andres: space

Yes

Perfect oil

Item Reviewed: Four Stroke Marine Motor Oils (WCF,WCT)
Discussion Url

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Bryan: space

Great value

Great value

Item Reviewed: Formula 4 Stroke Marine Motor Oils
Discussion Url

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Triston: space

I will buy this again

Great product, love it

Item Reviewed: Four Stroke Marine Motor Oils (WCF,WCT)
Discussion Url

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Russell: space

Oil

Use Amzoil in all my cars and motorcycles, jetski's etc.
Never had an oil related failure.
Will continue to trust Amzoil.

Item Reviewed: Four Stroke Marine Motor Oils (WCF,WCT)
Discussion Url

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Robert: space

Great stuff

Great stuff. Boat runs way better.

Item Reviewed: Four Stroke Marine Motor Oils (WCF,WCT)
Discussion Url

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Brian: space

Yes

Great product when two outboards cost 50k you use the best product possible. Please make filters for yamaha outboards

Item Reviewed: Four Stroke Marine Motor Oils (WCF,WCT)
Discussion Url

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Vic: space

Improved power

I recently started using Amsoil Marine in our Yamaha Jet Boat. With the boat being 6 years old, I immediately notice a quieter ride and was most impressed by the 5-7% thrust improvement (3-5mph). We will be using it in our jet skis next

Item Reviewed: Four Stroke Marine Motor Oils (WCF,WCT)
Discussion Url
View All 49 Reviews

Share your AMSOIL Experience
by writing a review


smaller | bigger

1-800-615-3709

Select your country.

Canada
Ships from Canada. Prices in CA dollars.
United States
Ships from USA. Prices in US dollars.

Price List Request

Receive wholesale price list in your email.