I had posted about this before, co worker of mine, 2008 F250 with the 5.4 Triton and he uses mostly Lucas for his oil changes,4-5 quarts Lucas, and 2-3 quarts 5W20 (7 qt capacity). Last Friday, he was on the road doing 55 mph when the oil pressure gauge dropped, he pulled over and the engine started knocking badly. He has it my cousins repair shop right now to determine if it can be fixed or if he'll need a new engine. I told him running so much Lucas didnt help the engine, his only reply was "it has 180,000 miles, you can expect things like that". He thinks it either spun a main or rod bearing, or the oil pump went out. What do yall think, do yall think the excess amounts and thickness of the Lucas, and also the fact that it has no additives, contributed to the failure?