AMSOIL Motor Oil Synthetic Oil

AMSOIL 15W-40 Heavy-Duty Diesel and Marine Oil

Dual-certified 15W-40 meeting API CK-4 and NMMA specs for mixed land and marine diesel operations.

AMSOIL 20W-50 Premium Protection Oil

Full synthetic 20W-50 upgrade for older high-mileage engines, pre-emissions vehicles, and air-cooled equipment.

AMSOIL 15W-40 Heavy-Duty Diesel Oil

API CK-4 synthetic in the standard 15W-40 viscosity, dramatically outperforming conventional diesel oils.

AMSOIL 15W-40 Signature Diesel Oil

AMSOIL's flagship Max-Duty 15W-40 for fleets demanding the longest drain intervals and lowest cost-per-mile.

AMSOIL 10W-40 Premium Protection Oil (Diesel)

Synthetic 10W-40 upgrade for older diesel engines and equipment requiring heavier multi-grade formulations.

AMSOIL 10W-30 Heavy-Duty Diesel Oil

API CK-4 full synthetic diesel oil for turbocharged trucks, farm equipment, and high-idle diesel applications.

AMSOIL 10W-30 Signature Diesel Oil

Max-Duty synthetic for mixed diesel fleets needing premium protection and maximum drain interval extension.

AMSOIL 5W-40 FS European Oil (Diesel)

Full SAPS diesel synthetic meeting VW 505.00/505.01 for turbocharged TDI and European diesel engines.

AMSOIL 5W-40 MS European Oil

Mid-SAPS European synthetic covering VW, BMW, and Mercedes-Benz specs for mixed diesel and gasoline fleets.

AMSOIL 5W-40 Heavy-Duty Diesel Oil

API CK-4 and ACEA E9 rated 5W-40 synthetic for on-highway and off-road turbocharged diesel engines.