"I didn't see any surprises in there at all,"  said owner/operator Gray when the engine was finally torn down.  In fact, analysis showed the engine was as wear-free as an engine in comparable service treated to 20 times the oil changes.

The results can only be credited to AMSOIL.  Gray used AMSOIL Synthetic 15-40 Heavy Duty Diesel and Marine Oil, an AMSOIL By-Pass Oil Filter and periodic oil analysis.

The E7-400 was town down by the local Mack dealership and it's parts were examined by a certified independent engine rater.  It showed only light to moderate wear throughout.

The rater even concluded that the engine parts could have been put right back on for continued use.

The tear down oil analysis confirmed the rater's findings.
The sample's content of wear metals was extremely low; one sixth the lead and one third the iron allowed by Mach condemnation limits --- all after
409,000 miles on a one time fill - without an oil change.