Quote: Well I worked in a Freightliner dealership back in 93/94. When the N14 cummins engine came out in the trucks. Cummins sent out a bulletin on extended oil changes. It provided that those companies who used oil analysis could go to 30,000 miles intervals with Mobil 1. Jim
Sure! The Tri-Synthetic formula of 1990s. Mobil 1s current SuperSyn formula that was introduced in 2002 has been under a lot fire lately for higher levels of Iron found in UOA reports. See also this Iron in M1 UOA’s? - link
