Synthetic SAE 10W-40
High Performance
Motor Oil

Recommended for Performance Engines Meets the Lubrication Requirements of Flat Tappet and Camshaft Style Engines. Click Here for More Information

Conventional motor oils tend to "boil off" in high temperatures, losing up to 25 percent of their original weight. These vaporized oils circulate poorly, reduce fuel efficiency and contribute to excessive emissions and engine wear. AMSOIL High Performance Synthetic 10W-40 Motor Oil resists vaporization. In fact, according to the NOACK Volatility Test, which measures the weight loss of an oil due to evaporation, AMSOIL High Performance 10W-40 only loses 7.0 percent of its weight in high temperature service, surpassing rigorous European standards set at 13 percent weight loss in high temperature testing. The superior vaporization resistance of AMSOIL High Performance 10W-40 keeps engine wear, oil consumption and emissions to a minimum, while keeping oil circulation efficient and fuel economy high.

Conventional oils oxidize in high operating temperatures, producing sludge and deposit build-up that contribute to corrosion, increased engine wear and decreased fuel economy. AMSOIL High Performance Synthetic 10W-40 Motor Oil resists oil breakdown, maintaining its cooling and lubricating properties and providing extended drain intervals. It continues to provide maximum protection at temperatures that oxidize conventional oils. The advanced heat transfer capabilities and high lubricity of AMSOIL High Performance Synthetic 10W-40 Motor Oil keep engines running in their optimum temperature range for top performance and long life.

Specifications API SL/CF, CI-4 API SJ, SH, SG ... MIL-PRF-2104G JASO-MA (Motorcycle)

AMSOIL High Performance Synthetic 10W-40 Motor Oil surpasses the North American SAE and European ACEA oil specifications for high temperature/high shear (HTHS) viscosity. It retains its viscosity at temperatures and loads that cause conventional oils to shear back to a lower viscosity. AMSOIL High Performance Synthetic 10W-40 Motor Oil maintains an extremely protective viscosity of 3.93 cP at 302°F (150°C) in the ASTM D 4683 High Temperature/High Shear Test, significantly exceeding test limits.

AMSOIL High Performance Synthetic 10W-40 Motor Oil remains fluid at temperatures as low as -54°F (-48°C), permitting easy engine cranking for quick starts. During sub-zero temperatures, it flows to all parts of the engine much quicker than conventional petroleum oils, greatly reducing the rate of wear and increasing engine life.

AMSOIL High Performance Synthetic 10W-40 Motor Oil is highly resistant to oxidation, running significantly cleaner than conventional motor oils. AMSOIL 10W-40 has a superior detergent/dispersant additive package that, when tested after tens of thousands of miles of use in the crankcase, still exhibits outstanding deposit control.

AMSOIL High Performance Synthetic 10W-40 Motor Oil contains special rust and corrosion inhibitors to protect iron parts, as well as copper, lead and aluminum bearing materials.

AMSOIL High Performance Synthetic 10W-40 Motor Oil features a superior synthetic composition and advanced performance additives, performing much longer than competing conventional and synthetic oils. No other major oil manufacturer matches AMSOIL's 25,000-mile or one-year drain interval recommendations.

AMSOIL High Performance Synthetic 10W-40 Motor Oil may be used in gasoline or diesel engines requiring oils meeting the specifications listed.

AMSOIL High Performance Synthetic 10W-40 Motor Oil is compatible with conventional petroleum oils; however, mixing AMSOIL 10W-40 with a conventional oil will shorten the drain period of AMSOIL 10W-40. Engine oil additives or after-market products are not recommended for use with AMSOIL 10W-40.

Service Life:

• In personal cars and light-duty trucks with non-turbocharged gasoline engines, drain oil at 25,000 miles or one-year intervals, whichever comes first.
• In turbocharged gasoline engines, change oil at three times the engine manufacturer's recommended drain interval or six months, whichever comes first.
• In high performance and racing engines, change oil at intervals specified by used oil analysis.
• In light-duty and non-turbocharged diesel engines, change oil at two or more times the engine manufacturer's recommended drain intervals if the findings of used oil analysis support those drain intervals or six months, whichever comes first.
• In heavy duty and turbocharged diesel engines, change oil at two or more times the engine manufacturer's recommended drain intervals if the findings of used oil analysis support those drain intervals or six months, whichever comes first.
• In motorcycle engines, change oil according to manufacturer's recommendations, without oil filtration. With oil filtration (AMSOIL SDF & SMF Filters), up to 2 times longer than manufacturer's recommendations or 6 months, whichever comes first.
• In marine craft and occasionally used gasoline engines, change oil at three times the engine manufacturer's recommended drain interval or one year, whichever comes first.
• In fleet vehicles and industrial gasoline engines, change oil at three times the engine manufacturer's recommended drain interval or six months, whichever comes first.

If the vehicle is equipped with an AMSOIL Ea Full Flow Oil Filter, the filter should be changed at 25,000-mile or one-year intervals (whichever comes first) in gasoline engines. Non-AMSOIL oil filters should be changed at the engine manufacturer's recommended filter change interval.

AMSOIL synthetic motor oils are fully compatible with conventional motor oil. For best results, however, use AMSOIL Engine Flush, then install AMSOIL synthetic motor oil.