AMSOIL 5W-40 HEAVY-DUTY 100% SYNTHETIC DIESEL OIL

AMSOIL 5W-40 Heavy-Duty 100% Synthetic Diesel Oil delivers serious wear protection and viscosity stability for diesel trucks and equipment that work hard every day. It is a direct upgrade over conventional, synthetic-blend, and competing synthetic diesel oils for operators who want longer equipment life and fewer unplanned repairs.

Diesel engines face punishing conditions. High combustion pressures, extreme heat, soot loading, and heavy loads all conspire to break down oil faster than most formulations can handle. In cold-weather starts, conventional 15W-40 oils thicken and resist flow, leaving critical components unprotected during the moments they need it most. A 5W-40 synthetic diesel oil that can handle both ends of the temperature spectrum is not a luxury in these applications. It is a practical necessity.

4X MORE WEAR PROTECTION
Ring and cylinder liner wear leads directly to increased oil consumption, lost compression, and reduced horsepower. Third-party testing in the Detroit Diesel DD13 Scuffing Test for specification DFS 93K222 shows AMSOIL Heavy-Duty Synthetic Diesel Oil delivers 4X more wear protection than the standard requires. That translates to longer equipment life and fewer tear-downs on engines like the Cummins 6.7L in Ram 2500 and 3500 trucks, the Duramax 6.6L in Chevy and GMC HD pickups, and the Power Stroke 6.7L in Ford Super Duty applications. For fleets running Volvo D13, Mack MP8, or Detroit DD13 and DD15 engines, this level of protection directly reduces maintenance costs and unscheduled downtime.

VISCOSITY CONTROL UNDER SOOT AND HEAT
Soot is the silent killer of diesel oil. As soot particles accumulate, they can agglomerate into larger, abrasive clusters that thicken the oil and accelerate wear. AMSOIL Heavy-Duty Synthetic Diesel Oil uses advanced synthetic base oils and detergent/dispersant additives to keep soot particles suspended independently, preventing them from clustering together. The 5W-40 viscosity grade maintains a viscosity index of 178 (ASTM D2270), which means the oil resists thinning at high temperatures while still flowing freely when cold. Low NOACK volatility of 9.2% weight loss (ASTM D5800) means the oil retains its viscosity after sustained high-temperature service rather than burning off its lighter molecules and leaving behind a thickened, less effective lubricant.

UP TO 66% LESS OIL CONSUMPTION
Burn-off matters. Every quart of oil an engine consumes is oil vapor entering the combustion chamber, potentially fouling emissions equipment and costing money in top-offs. In the Caterpillar-1N oil consumption test, AMSOIL Heavy-Duty Synthetic Diesel Oil recorded 0.17 g/kWh of oil consumption compared to the API CK-4 limit of 0.5 g/kWh. That is up to 66 percent less oil consumption than the standard allows. For a Ram 3500 towing through the mountains, a Caterpillar excavator running 10-hour days, or a Peterbilt logging interstate miles, reduced oil consumption means fewer stops, lower operating costs, and less stress on the diesel particulate filter.

COLD-WEATHER PERFORMANCE
The 5W-40 viscosity grade flows at significantly lower temperatures than a conventional 15W-40, providing faster oil circulation on cold starts. The cold-crank simulator viscosity for the 5W-40 is 5581 cP at -30°C (ASTM D5293), and the pour point reaches -42°C (-44°F) per ASTM D97. For operators starting equipment in sub-zero conditions, whether on a jobsite in Minnesota or a truck yard in northern Alberta, this means the oil reaches bearings, turbochargers, and cylinder walls faster. Faster oil delivery at startup reduces the dry-start wear that shortens engine life.

SPECIFICATIONS AND COMPATIBILITY
AMSOIL 5W-40 Heavy-Duty Synthetic Diesel Oil meets or exceeds a wide range of OEM and industry specifications: API CK-4, CJ-4, CI-4+, CF, and CF-2. It also meets Volvo VDS4.5, VDS4, and VDS3; Mack EOS-4.5 and EO-O; Renault RLD-4 and RLD-3; Cummins CES 20086 and CES 20081; Caterpillar ECF-2, ECF-3, and ECF-1-a; DFS 93K222; DDC 93K218, 93K215, and 93K214; ACEA E9 and E7; MB 228.31; MAN 3575; MTU Type 2.1, Type II, and Type I; JASO DH-2; JASO MA and MA2; Deutz DQC III-10LA; Chrysler MS 10902; Ford WSS-M2C171-F1; and Allison TES439. All viscosities are also capable of gasoline service per API SN. The oil is compatible with conventional and other synthetic oils, though mixing will reduce the performance benefits of the AMSOIL formulation. Aftermarket oil additives are not recommended.

SERVICE LIFE
AMSOIL Heavy-Duty Synthetic Diesel Oil is recommended for the drain intervals stated by the original equipment manufacturer. Intervals may be extended beyond the OEM recommendation with oil analysis. For competition or severe-duty use, oil analysis should be used to determine the appropriate drain interval.