AMSOIL 5W-40 100% Synthetic Metric Motorcycle Oil

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AMSOIL 5W-40 100% Synthetic Metric Motorcycle Oil

AMSOIL 5W-40 100% Synthetic Metric Motorcycle Oil (MMF) is the popular SAE 5W-40 wet-clutch motorcycle oil for European-spec metric bikes. The synthetic formulation is engineered for Aprilia, Benelli, BMW, Can-Am, Husqvarna, Moto Guzzi, and other four-stroke street motorcycles whose owner manual calls for a 5W-40 grade. It meets API SN, API GL-1, and JASO MA/MA-2, and the 5W cold-cranking number supports cold-climate cold starts that thicker viscosity grades cannot match.

Cold-start flow for low-temperature riding

The 5W cold-cranking number lets MMF circulate quickly at startup, which is the highest-wear moment in any four-stroke metric engine. A pour point of -47 degrees C (-53 degrees F) under ASTM D97 keeps the oil pumpable at cold-morning temperatures that drop a heavier 10W or 20W grade toward the floor of the case. The synthetic base also holds a viscosity index of 176 under ASTM D2270, so the oil thins less between cold start and operating temperature than a typical petroleum motorcycle oil and reaches the upper end faster on early-season and shoulder-season rides.

High-temperature film strength and wear protection

At operating temperature, MMF develops a 16.0 cSt kinematic viscosity at 100 degrees C and a 4.3 cP high-temperature high-shear viscosity at 150 degrees C under ASTM D4683. The HTHS number is what protects cam lobes, rod bearings, transmission gear teeth, and other load-bearing surfaces under high rpm and heat. A heavy treatment of anti-wear additives backs up the film strength, with a Four-Ball Wear Test scar diameter of 0.35 mm at 40 kg, 150 degrees C, 1,800 rpm, and one hour under ASTM D4172.

The synthetic base also resists thermal volatility, with a NOACK weight loss of 5.9 percent under ASTM D5800. Lower NOACK reduces oil burn-off through the PCV and combustion path, which keeps top-up intervals long and helps prevent damaging sludge and carbon deposits.

Wet-clutch friction control without friction modifiers

A wet-clutch motorcycle needs an oil that does not carry the friction modifiers used in modern passenger-car formulations. MMF contains no friction modifiers and meets both JASO MA and JASO MA-2 for smooth shifting and positive clutch engagement on BMW, Aprilia, Moto Guzzi, Husqvarna, and other metric bikes that share engine and transmission oil. A total base number of 11.6 under ASTM D2896 neutralizes the acids that degrade clutch material across the service interval, supporting consistent clutch feel as the oil works through its drain.

Foam resistance for high-rpm street and adventure use

High-rpm operation drives foam in motorcycle sumps, and foam bubbles collapse between gear teeth and engine components, allowing metal-to-metal contact and wear. MMF contains advanced anti-foam additives, and under the ASTM D892 foam sequence (I, II, III) the oil returns 0/10/0. That foam-control margin supports reliable wear protection on sport, sport-touring, and adventure bikes ridden hard.

Rust protection for stored and short-trip motorcycles

Adventure, touring, and dual-sport bikes often sit parked through winter, and short rides never bring the oil up to a temperature that boils off internal moisture. MMF contains specific anti-corrosion agents and passes the ASTM D1748 humidity cabinet rust test. The 11.6 TBN reserve also protects against acid corrosion that can pit camshafts, lifters, and roller bearings on motorcycles that see long off-season storage.

Recommended applications and service intervals

Use AMSOIL 5W-40 Synthetic Metric Motorcycle Oil in Aprilia, Benelli, BMW, Can-Am, Husqvarna, Moto Guzzi, and other motorcycles that require a 5W-40 motorcycle oil and any of the following specifications: API SN, API GL-1, or JASO MA/MA-2. The oil is not recommended for applications that require an API GL-4 or GL-5 gear oil.

• Engines and transmissions, normal service: up to twice the motorcycle manufacturer change interval (miles, hours, or one year, whichever comes first) when paired with an AMSOIL Motorcycle Oil Filter.
• Non-AMSOIL oil filter fitted: change the oil and filter at the motorcycle manufacturer's recommended interval.
• Racing or modified engines: extended drain intervals do not apply, and oil change is at the owner's discretion.
• Outside the United States and Canada: confirm application match against the local owner manual viscosity and JASO specification before service.

MMF is compatible with other synthetic and conventional motor oils, but mixing shortens its service life and reduces performance benefits, so extended drain intervals are not supported on mixed oil. Aftermarket oil additives are not recommended for use with AMSOIL Synthetic Motorcycle Oil. For fit by bike, work through the AMSOIL vehicle lookup guide before ordering.

Typical technical properties

Order AMSOIL 5W-40 100% Synthetic Metric Motorcycle Oil

AMSOIL 5W-40 100% Synthetic Metric Motorcycle Oil ships in the quart bottle (MMFQT-EA) and the case of 12 quarts (MMFQT-CA). The product is Warranty Secure, a high-performance replacement for vehicle-manufacturer-branded products, and is backed by the AMSOIL Limited Warranty when used as directed in motorcycles that specify a 5W-40 motorcycle oil. For viscosity selection across the metric range, review the AMSOIL motorcycle oil guide, and to match the right oil to a specific make, model, and year, work through the AMSOIL vehicle lookup guide before placing an order. Order Now.

Frequently asked questions