According to Pennzoil-Quaker State Co., Pennzoil Long-Life heavy-duty engine oil has passed the testing required to meet the newest oil classification for heavy-duty engines, API's CI-4 spec for '02 and older diesels.
“We were one of the first companies to offer an API CH-4 oil when that classification was approved and we are continuing that trend by being among the first with a product to meet the new CI-4 classification,” stated Kristin Stewart, senior brand manager.
In order to qualify for CI-4, the oil was subjected to a battery of lab bench tests and engine tests designed to replicate the operating conditions of '02 diesels, most of which will have exhaust-gas-recirculation systems.