COLONIAL HEIGHTS, VIRGINIA I didn’t see any surprises in there at all. Based on my experience with AMSOIL Motor Oil, it came out the way we expected, said owner/ operator Haywood Gray (right) of his 1990 Mack E7-400 engine. It came out in good shape, exactly what you expect for a well-maintained engine with 630,000 miles. Yet the engines oil had not been changed for 409,000 miles!
Gray began using AMSOIL Synthetic Heavy-Duty Diesel and Marine 15W-40 Motor Oil (AME) in the E9-400 V-8 engine of his first truck, a 1984 Mack, after the engine accumulated 45,000 miles. For 280,000 miles, Gray changed his oil at 40,000-to 60,000-mile intervals though his oil analysis reports showed, without exception, that the oil was good for continued use. At 325,000 miles, Gray increased his oil drain interval to 100,000 miles. The engine was torn down at 600,000 miles when Gray decided to sell the truck. The cylinder liners, bearings, pistons, rings and oil pump, all treated to extended oil drain intervals with AMSOIL, were found to be in excellent condition. Gray continued using AMSOIL AME in the engine of his new truck, a 1990 Mack with a E7-400 engine. With the new truck, instead of using 100,000 mile drain intervals, Gray began basing his oil drains on the findings of a used oil analysis program. He also installed an AMSOIL By-Pass Oil Filter. After 630,000 miles total and 409,000 miles without an oil change, the E7-400 engine was torn down by the local Mack dealership in December 1996 and its parts were examined by an engine rater from a major oil additive manufacturer.