Synthetic Diesel Oil

Maximum Duty Synthetic Diesel Oil protects your investment in diesel power and confidently extend drain intervals with our top-grade synthetic diesel oil. AMSOIL Signature Series Maximum Duty delivers 6X better wear protection than required by the Detroit Diesel DD13 Scuffing Test for Specification DFS 93K222. 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.

Maximum Engine Protection
Wear on rings and cylinder liners leads to increased oil consumption and loss of compression, resulting in reduced horsepower and fuel economy. Independent testing shows AMSOIL Signature Series Maximum Duty delivers 6X more wear protection*, delivering the security of providing your diesel the extra protection it deserves.

*Based on independent testing in the Detroit Diesel DD13 Scuffing Test for specification DFS 93K222 using a 5W-30 as worst-case representation.

Excels in Extreme Temperatures
AMSOIL Signature Series Maximum Duty resists thermal (heat) breakdown better than conventional and competing synthetic diesel oils. Unlike conventional oils, Signature Series contains no wax, staying fluid in sub-zero temperatures for easier starting, improved oil flow and reduced wear.

Viscosity Control
Using top-tier synthetic base oils, AMSOIL Signature Series Maximum Duty is naturally resistant to oxidation and the thickening effects of soot contamination. That, along with boosted detergent/dispersant additives, keeps soot particles suspended independently, helping prevent the formation of larger, wear-causing particles. Viscosity increase is minimized and soot-related wear is controlled. Lower volatility also helps Signature Series Max-Duty retain its viscosity after high-temperature service for maximum engine protection and efficiency.

Minimizes Oil Consumption
AMSOIL Signature Series Maximum Duty has a low rate of volatility (burn-off), reducing oil consumption during operation and passing less oil vapor into the combustion chamber. It provides up to 76 percent less oil consumption than required by the API CK-4 standard in the Caterpillar-1N oil consumption test.

Signature Series Diesel Oil 15W-40Signature Series Maximum Duty Synthetic Diesel Oil 15W-40

Synthetic 5W-40Signature Series Maximum Duty Synthetic Diesel Oil 5W-40

Diesel Oil 0W-40Signature Series Maximum Duty Synthetic Diesel Oil 0W-40


Synthetic Diesel Oil 5W-30Signature Series Maximum Duty Synthetic Diesel Oil 5W-30

Signature Series Maximum Duty Synthetic Diesel Oil 10W-30Signature Series Maximum Duty Synthetic 10W-30

Diesel Fuel Additives
Diesel Motor Oil