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Protect your investment in diesel power and confidently extend drain intervals with our top-grade synthetic diesel oil.
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NEW AMSOIL Synthetic Diesel Oils

Diesel oil is undergoing a major change. The new API CK-4 and FA-4 diesel oil specifications are here, and an overhauled AMSOIL synthetic diesel oil lineup launches Feb. 6, bringing even better protection and performance with it.

AMSOIL Signature Series Max-Duty Synthetic Diesel Oil 
AMSOIL Signature Series Max-Duty Synthetic Diesel Oil delivers 4X better cold-temperature performance when compared to SAE 15W-40 oil in ASTM D5293 cold cranking viscosity test. Advanced synthetic technology provides excellent viscosity control and outstanding extreme-temperature performance, while minimizing oil consumption. The result: protection that’s boosted to the max.

AMSOIL Signature Series Heavy-Duty Synthetic Diesel Oil
AMSOIL Heavy-Duty Synthetic Diesel Oil is formulated for hard-working equipment. It is engineered to provide 4X better wear protection than required by the Detroit Diesel DD13 Scuffing Test for Specification DFS 93K222, giving you the edge to keep trucks and equipment operating at peak performance. Heavy-Duty Synthetic Diesel Oil offers outstanding value and provides excellent protection for customers seeking an upgrade over conventional, synthetic-blend or competing synthetic diesel oils. 
Diesel Engine Service Life
  • Three times (3X) OEM recommendation, not to exceed 60,000 miles/600 hours or one year, whichever comes first.
  • Two times (2X) OEM1 recommendation, not to exceed 25,000 miles or one year, whichever comes first.
  • Two times (2X) OEM1 recommendation, not to exceed 15,000 miles or one year, whichever comes first.
Note: Extended drain intervals are not recommended for performance-modified engines, when using biofuels containing more than 10 percent ethanol or 15 percent biodiesel (B15) or for 2007-2009 Caterpillar* C13 and C15 on-highway engines. Extend drain intervals beyond OEM recommendations in these instances only with oil analysis. Note: 2007-2010 Dodge**, Ford** and GM** turbodiesel pickups are also not recommended for extended drain intervals when using DHD.
SAE 15W-40 Heavy-Duty Diesel and Marine Oil
Series 3000 5W-30 Synthetic Heavy Duty Diesel Oil
Premium Protection 20W-50 Synthetic Motor Oil
Premium Protection 10w-40 Synthetic Motor Oil
OE 15W-40 Synthetic Diesel Oil
OE 10W-30 Synthetic Diesel Oil
10W-30/SAE 30 Synthetic Heavy Duty Diesel Oil

Protection Boosted to the Max

A diesel truck is a serious investment – don’t skimp on protection. AMSOIL synthetic diesel oils provide the ultimate protection for your hard-working diesel engine, preserving the horsepower you crave and keeping you on the road.

The extreme heat produced by turbochargers can be brutal on your oil. If your oil fails and your turbos are damaged, you start losing horsepower – or worse. Our synthetic diesel oils are designed to protect your horsepower. We build extra turbo protection into every drop, preserving turbos and delivering reliable horsepower.