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10W-40 Synthetic Small Engine Oil - Commercial Grade (ASF)

 10W-40 Synthetic Small Engine Oil - Commercial Grade (ASF)
Product Code: ASF • Brand: AMSOIL

Formulated to outperform passenger-car/light-truck oils, AMSOIL Synthetic Small-Engine Oil protects against wear, deposits and oil consumption in over-worked, under-maintained small engines professionals rely on to make a living.

Package sizes include:

1-Quart Bottle
1-Gallon Bottle
5-Gallon Pail
55-Gallon Drum

See Pricing or Place an Order
MSDSData Sheet

Product Details

Product Applications

Use the appropriate viscosity of Synthetic Small-Engine Oil in applications that require any of the following specifications:

• API SL, SJ, SH, SG...(Gasoline)
• API CF, CD (Diesel)
• JASO MA/MA2 (Wet Clutch)

Use 10W-40 Synthetic Small-Engine Oil in small engines found in (not limited to) mowers (zero-turn, riding, stand-on, push), generators, power washers and other equipment that requires SAE 10W-40 or 15W-40 motor oil, including (and not limited to):

• Mowers (zero-turn, riding, stand-on, push)
• Generators
• Power washers

Made by (and not limited to):

• Kubota®
• Kawasaki®
• Robin®
• Onan®
• Linamar®
• Vanguard®

Equipment types include (and not limited to):

• Maintenance equipment
• Tractors
• Lawn and garden equipment
• Compactors
• Pumps
• Light towers
• Log splitters
• Welders
• Cement mixers and trowels
• Skid-steers
• Excavators
• Rototillers
• Compressors

Product Description

Using a high-quality small-engine oil has a direct effect on efficiency and profitability. Over time, wear and deposits rob small engines of power, reducing productivity. High heat can cause oils not formulated for severe service to boil off, leading to increased oil consumption, forcing the work crew to continually top-off the oil. AMSOIL Synthetic Small-Engine Oil is a tough formulation designed to preserve engine power while fighting oil consumption, helping professionals work more efficiently and save money on maintenance.

Fights Power Loss

Continuous severe-service operation accelerates wear and leads to harmful deposits that can stick rings and valves, robbing the engine of power. Power loss means less productivity and more maintenance. Synthetic Small-Engine Oil is a tough synthetic oil chemically engineered with anti-wear additives and heat-resistant anti-oxidants that protect pistons and bearings. After 500 hours of severe-service lab testing, AMSOIL 10W-40 Synthetic Small-Engine Oil virtually eliminated wear and deposits, helping preserve engine power and ensure productivity (see image).

Piston Deposit Test

Reduces Oil Consumption

Commercial-grade small engines run hot, with oil temperatures reaching 250°F and higher. High heat causes standard-service oils to vaporize and exit the crankcase vent, leading to increased oil consumption. Heat also breaks down oil and forms deposits that lead to piston-ring sticking. Stuck rings fail to seal the combustion chamber and keep oil from entering and burning. As a result, workers must diligently check and top-off the oil to ensure the engine is protected, wasting time and money. AMSOIL Synthetic Small-Engine Oil's heat-stable synthetic base oils withstand extreme heat better than other oils. In lab testing 10W-40 Synthetic Small-Engine Oil reduced oil consumption 61 percent compared to three leading 10W-40/SAE 40 motor oils**. It keeps engines clean for peak efficiency and reduced maintenance.

diesel oil Scuffing Test

Long Service Life

On busy job sites, equipment maintenance can easily be delayed or overlooked completely. If using standard-service motor oils, high rates of oil consumption can leave the engine unprotected for extended periods, and it's only a matter of time before catastrophic wear sets in. AMSOIL Synthetic Small-Engine Oil lasts longer than conventional oil, providing peace of mind that engines are protected, even when maintenance is delayed.

• Preserves engine power
• Helps cut maintenance costs
• Fights heat and deposits


AMSOIL Synthetic Small-Engine Oil is compatible with other conventional and synthetic motor oils. Mixing AMSOIL motor oils with other oils, however, will shorten the oil's life expectancy and reduce the performance benefits.

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


AMSOIL Synthetic Small-Engine Oil is a long-life formulation that can last longer than conventional petroleum oils. It provides an extra measure of protection when equipment typically goes longer between oil changes than is recommended by the equipment manufacturer. Due to wide variances in operating conditions and maintenance practices, AMSOIL recommends extending drain intervals when monitored by oil analysis or following the equipment manufacturer-established drain intervals.


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 ASF.

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

Technical Data

  10W-40 Synthetic Small Engine Oil (ASF)
Kinematic Viscosity @ 100°C, cSt (ASTM D-445)14.5
Kinematic Viscosity @ 40°C, cSt (ASTM D-445)96.6
Viscosity Index (ASTM D-2270)156
CCS Viscosity, cP (ASTM D5293)6057 (-25)
Pour Point °C (°F) (ASTM D-97)-39 (-38)
Flash Point °C (°F) (ASTM D-92)232 (450)
Fire Point °C (°F) (ASTM D-92)252 (486)
Four Ball Wear Test
(ASTM D-4172B: 40 kg, 75°C, 1200 rpm, 1 hour), Scar, mm
Noack Volatility, % weight loss (g/100g) (ASTM D-5800)3.7%
High Temperature/High Shear @ 150°C and 1.0 X 106 s-1, cP (ASTM D 4683), cP4.4
Total Base Number8.5

 10W-40 Synthetic Small Engine Oil - Commercial Grade (ASF)

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