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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
MSDS Data 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

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

Did this product meet your expectations?

(click on a star to rate)

Product Name: Four Stroke Marine Motor Oils (WCF,WCT)
Current Rating: 4.89 out of 5 stars
Votes & Reviews: 42 vote(s) and 37 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 Bobby: space

Best for my boat!

I have been using this in my Yamaha 150 4 stroke for over 10 years. I recently replaced the balancer and had the opportunity to inspect the engine internally from the bottom end. I observed absolutely zero wear on visible internal engine parts and the engine was so clean inside it looked brand new!

Item Reviewed: Four Stroke Marine Motor Oils (WCF,WCT)
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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 West Coast Boater: space

Trusted product

Use it on both my Yamaha 2016 115 hp and 2017 9.9 high thrust motors.

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 Tomace: space

Runs in everything

Keep the motor cool and quiet

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 Chris: space

Love this stuff

Just recently bought a chaparral SSI sport bowrider boat took it out twice and got 47 miles per hour. change the oil to amsoil 10w 30 for boats take it back to the lake and ran it hard and got a solid 50 miles per hour.

Item Reviewed: Four Stroke Marine Motor Oils (WCF,WCT)
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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 Reeling: space

Great product

I use Amsoil in my boat for the last three years. The engine seems more quiet and the oil level stays at the same level throughout the boating season.

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 Chris: space

So far so good

I bought a Seadoo GTR 215 supercharged unit and was looking for oil to complete an oil change. I've had great success with Amsoil in the past in sleds and atvs so I wanted to use in my Seadoo. I had read mixed reviews about using the Amsoil Synthetic marine oil in the supercharged skis due to supercharger clutch slip. But so far I've had no issues after approx 12 hours of riding.

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 Millerlite66: space

Works for me

I run this oil in a 1988 Glastron. I'm the second owner. I have used the 10w40 Marine oil for the 18 years I have owned this boat. It has a 7.4 liter GM big block in it . I have never had an engine problem that had to do with lubrication. Just sayin.

Item Reviewed: Four Stroke Marine Motor Oils (WCF,WCT)
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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 Mitchell: space

Not sure.

Can't tell the difference.

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 Louie: space

Outboards

Oil I could trust running offshore

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 Mismo Titan: space

Simply the Best

We run our sea doos hard and this oil has never let us down. For supercharged skis there are no friction modifiers and it's JASO MA2 which is safe for our superchargers. I've been running amsoil in all my products for a while now and won't run anything else.

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