Specially engineered for maximum performance in engines and transmissions on four-stroke metric sport bikes, cruisers, touring motorcycles, and adventure bikes. Wet-clutch compatible for smooth, confident shifts. Robust heat resistance and wear protection. Maintains viscosity. Advanced detergency cleans critical components.
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Product data sheets
View, download, or save a copy of the Product Data Sheet or Safety Data Sheet for AMSOIL 15W-50 100% Synthetic Metric Motorcycle Oil.
AMSOIL 15W-50 100% Synthetic Metric Motorcycle Oil (MFF) is the popular SAE 15W-50 synthetic motorcycle oil for four-stroke metric sport bikes, adventure bikes, touring bikes, and large-displacement cruisers that specify a 15W-50 grade. The heavier viscosity targets high-output engines from BMW, Ducati, KTM, Royal Enfield, Triumph, and Yamaha, plus high-revving inline-fours like the Suzuki Hayabusa and Kawasaki ZX-14R that punish thinner grades when oil temperatures climb.
Heavier 15W-50 film strength for high-output engines
Big metric engines, air-cooled cruisers, and liter-class sport bikes raise oil temperatures fast in summer traffic, on long highway pulls, and during aggressive riding. AMSOIL 15W-50 Synthetic Metric Motorcycle Oil exceeds industry standards for high-temperature film strength to deliver excellent wear protection, with a measured kinematic viscosity of 20.2 cSt at 100 degrees C and a high-temperature/high-shear viscosity of 5.7 cP at 150 degrees C (ASTM D445, ASTM D4683). The 15W-50 grade keeps a heavier hydrodynamic film between the cam lobes, rod bearings, transmission gears, and clutch packs when oil temperatures climb past the comfort zone of a 10W-40 or 5W-40.
The synthetic base oils resist oxidation in extreme heat, while a heavy treatment of anti-wear additives limits metal-to-metal contact under load. A 0.39 mm Four-Ball wear scar (ASTM D4172, 40 kg, 150 degrees C, 1800 rpm, 1 hour) quantifies the wear-control margin built into the formula.
Low volatility and oxidation control to fight oil consumption
Metric sport bikes and adventure twins frequently see sustained high-rpm operation that boils off lighter oil fractions and accelerates oxidation. The 15W-50 grade posts a low NOACK volatility of 3.8 percent weight loss (ASTM D5800), so less oil burns off through the ring pack and PCV path. Lower volatility helps maintain the as-installed viscosity through the service interval, reduces top-off frequency on hard-ridden bikes, and limits deposit formation on pistons and ring lands.
Optimized antioxidant additives are engineered to prevent damaging sludge and carbon deposit formation, supporting cleaner pistons, cooler rings, and steadier compression over time.
JASO MA/MA2 wet-clutch friction for smooth shifting
Wet clutches require a motorcycle-specific oil, not a passenger-car oil that contains modern friction modifiers. AMSOIL 15W-50 Synthetic Metric Motorcycle Oil meets JASO MA and JASO MA2 and contains no friction modifiers, so the clutch grips without slip and the gearbox shifts cleanly under power. The formula is engineered to control heat and prevent slippage and glazing, which supports long clutch life on high-torque twins and high-output inline-fours that drag clutches during launches.
Anti-foam additives for high-rpm protection
High-rpm operation churns motor oil and can create foam bubbles that collapse when traveling between gear teeth and engine components, allowing metal surfaces to contact and cause wear. AMSOIL 15W-50 Synthetic Metric Motorcycle Oil contains advanced anti-foam additives and posts an ASTM D892 foam sequence I/II/III result of 0/40/0 mL, supporting reliable wear protection during sustained high-rpm pulls and redline shifts.
Rust and corrosion protection for stored and short-trip bikes
Motorcycles often sit through winters or weather windows, and short rides never bring the oil up to a temperature that boils off internal moisture. Standing humidity drives roller-bearing failure, ring-land corrosion, and blow-by. AMSOIL 15W-50 Synthetic Metric Motorcycle Oil contains special anti-corrosion agents and passes the ASTM D1748 humidity cabinet rust test. A high total base number (TBN) of 11.6 (ASTM D2896) neutralizes acids that build up during combustion and short-trip cycles, helping protect critical surfaces and maintain internal engine cleanliness during storage.
Recommended applications and service intervals
Use AMSOIL 15W-50 Synthetic Metric Motorcycle Oil in BMW, Ducati, KTM, Royal Enfield, Triumph, Yamaha, and other motorcycles that require a 15W-50 motorcycle oil meeting API SN and JASO MA/MA2. The formula is not recommended for applications requiring an API GL-4 or GL-5 gear oil. For fit by bike, see the AMSOIL vehicle lookup guide.
Normal service with an AMSOIL Oil Filter: up to twice the motorcycle manufacturer-recommended change interval (miles, hours, or one year, whichever comes first).
With a non-AMSOIL oil filter: change the oil and filter at the manufacturer-recommended intervals.
Racing or modified engines: extended drain intervals are not recommended; oil changes are at the owner's discretion.
Outside the United States and Canada: follow the recommendations published in the local market.
Pair MFF with an AMSOIL Motorcycle Oil Filter to support extended drains. The oil is compatible with other synthetic and conventional motor oils, but mixing shortens service life and reduces performance benefits, so extended drain intervals are not supported on mixed oil. Aftermarket oil additives are not recommended with AMSOIL Synthetic Motorcycle Oil. The product is Warranty Secure and is a high-performance replacement for vehicle-manufacturer-branded products without voiding the factory warranty when used as directed.
Typical technical properties
Property
Value
Kinematic Viscosity at 100 degrees C, cSt (ASTM D445)
20.2
Kinematic Viscosity at 40 degrees C, cSt (ASTM D445)
140.7
Viscosity Index (ASTM D2270)
165
Pour Point, degrees C (degrees F) (ASTM D97)
-39 (-38)
Flash Point, degrees C (degrees F) (ASTM D92)
238 (460)
Fire Point, degrees C (degrees F) (ASTM D92)
274 (525)
NOACK Volatility, percent weight loss (ASTM D5800)
3.8
High-Temperature/High-Shear Viscosity at 150 degrees C, cP (ASTM D4683)
5.7
Total Base Number (ASTM D2896)
11.6
Four-Ball Wear Test, Scar Diameter, mm (ASTM D4172)
0.39
Foam Test, Sequence I/II/III, mL (ASTM D892)
0/40/0
Rust Test, Humidity Cabinet (ASTM D1748)
No Rust, Pass
Order AMSOIL 15W-50 100% Synthetic Metric Motorcycle Oil
AMSOIL 15W-50 100% Synthetic Metric Motorcycle Oil ships in the quart bottle (MFFQT-EA) and case of 12 quarts (MFFQT-CA). The product is Warranty Secure and is backed by the AMSOIL Limited Warranty when used as directed. For category context across metric, V-twin, and dirt-bike use, review the AMSOIL motorcycle oil guide and match the right product with the AMSOIL vehicle lookup guide before placing an order. Order Now.
What motorcycles take AMSOIL 15W-50 Metric Motorcycle Oil?
The 15W-50 grade is recommended for BMW, Ducati, KTM, Royal Enfield, Triumph, Yamaha, and other motorcycles that specify a 15W-50 motorcycle oil meeting API SN and JASO MA/MA2. The heavier grade also suits high-output inline-fours such as the Suzuki Hayabusa and Kawasaki ZX-14R, along with large-displacement air-cooled cruisers when the owner manual calls for SAE 15W-50.
Is AMSOIL 15W-50 Metric Motorcycle Oil JASO MA/MA2 wet-clutch compatible?
Yes. The 15W-50 grade meets JASO MA and JASO MA2 and contains no friction modifiers, so it supports smooth shifting and positive clutch engagement in wet-clutch motorcycles. It also meets API SN.
Will using a synthetic motorcycle oil void the factory warranty?
No. Using AMSOIL synthetic lubricants does not void a factory warranty. AMSOIL 15W-50 Synthetic Metric Motorcycle Oil is Warranty Secure and is backed by the AMSOIL Limited Warranty when used in motorcycles that specify a 15W-50 motorcycle oil and the listed specifications.
How long can the oil go between changes?
Paired with an AMSOIL Oil Filter, MFF supports up to twice the motorcycle manufacturer-recommended change interval (miles, hours, or one year, whichever comes first) in normal service. When a non-AMSOIL filter is fitted, change the oil and filter at the manufacturer-recommended intervals. Racing and modified engines are excluded from extended drain intervals.
Can 15W-50 Metric be substituted for a 10W-40 or 5W-40 in a metric bike?
No. Use the viscosity grade printed in the motorcycle owner manual. The 15W-50 grade is reserved for engines that specify SAE 15W-50, and the 10W-40 (MCF), 5W-40 (MMF), and 10W-30 (MCT) grades cover their own application sets within the AMSOIL Synthetic Metric Motorcycle Oil family. Cross-grade substitution can affect clearances, oil pressure, and emissions controls.
Can the oil be mixed with conventional or other synthetic motorcycle oils?
The product is compatible with other synthetic and conventional motor oils, but mixing shortens service life and reduces performance benefits. Extended drain intervals are not supported on mixed oil. Aftermarket oil additives are not recommended with AMSOIL Synthetic Motorcycle Oil.
Does AMSOIL 15W-50 Metric Motorcycle Oil protect a stored or short-trip bike from rust?
Yes. Storage humidity and short-distance riding promote internal rust that can cause roller-bearing failure, wear, and blow-by. The 15W-50 grade contains specific anti-corrosion agents, passes the ASTM D1748 humidity cabinet rust test, and posts a total base number of 11.6 to neutralize acids built up during short-trip combustion cycles.
