[Ol'Rattler]

This applies to gassers, diesels don't do a pressure leak down test

To add a little science to it, Diesels don't have an evaporative system like gassers do because they don't need an evaporative system. Diesels are simply vented to atmosphere.

The reason is that the flash point of gasoline is minus 45F were Diesels flash point is plus 125F. The flash point is the lowest temp a flammable liquid will give off vapors that an ignition source can ignite.

Diesel looses almost nothing to evaporation in storage were gasoline looses a lot if it is not in a sealed container or system.