Pennzoil Long-Life Heavy Duty Engine Oil has passed the rigorous testing required to meet the newest oil classification for heavy duty diesel engines. The new CI-4 specification was developed specifically to meet the higher demands of lower-emission 2002 diesel engines, which are expected to generate significantly more soot and run at hotter temperatures than current diesels. Fleets can use Pennzoil Long- Life oil in 2002 engines, and in older engines requiring API CH-4, CG-4, CF-4 or CF performance oils.