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.

New Specifications, New Diesel Oils

The new API CK-4 and FA-4 specifications focus on these six goals:

  • Reduced emissions
  • Improved fuel economy
  • Stronger oxidation stability
  • Better shear stability
  • Increased resistance to aeration
  • Improved wear protection

The new API CK-4 specification is designed for current model-year and older diesel engines and is backward-compatible with API CJ-4 (and prior) oils. Going forward, all applications calling for a diesel oil meeting API CJ-4 (and prior) specifications should use an API CK-4 diesel oil.

The new API FA-4 specification is designed to further improve fuel economy and reduce emissions. FA-4 oils are not backward-compatible and may only be used in certain 2017 and newer over-the-road trucks, when approved by the original equipment manufacturer (OEM).

Launching in February, new AMSOIL Signature Series Max-Duty Synthetic Diesel Oil and Heavy-Duty Synthetic Diesel Oil will replace AMSOIL Premium Synthetic Diesel Oil (DEO, DME) and OE Synthetic Diesel Oil (OEC, OED).

AMSOIL Signature Series Max-Duty Synthetic Diesel Oil – more info here.