3. Military specifications

3.1 U.S. military specifications

As early as 1941, the US Army was the first to draw up motor oil specifications for its own use. For many years, these specifications were the benchmarks to which the whole world conformed. Since then, for civilian applications, they have been progressively superseded by API service classifications, from which they are largely inspired.

These specifications, known by the acronyms MIL-L... (Military Lubricant...), or more recently MIL-PRF... (Military Performance Requirement Fluid...), define oils for gasoline and diesel engines and transmissions.

• Some of these are multifunctional oils for "tactical service", i.e. "single" oils for use in all army vehicles during military operations....