Dear AMSOIL:

I have been using AMSOIL Synthetic Diesel Engine Oil and the AMSOIL Dual-Gard By-Pass Filtration System, along with used oil analysis, for nearly three years. My 1997 Mack CH613 had 176,000 miles on it when I began using AMSOIL motor oil and the Dual-Gard System. At the time I bought this truck, the company I am leased to bought a number of identical trucks for their fleet. All of these trucks operate in much the same way, including operating environment, type of haul, etc. These trucks also have a dash mounted digital display of the lifetime average fuel economy. At this time my trucks average is 6.78 MPG, and the company trucks range from 5.8 to 6.2 MPG. The difference between 6.78 and a fleet average of 6 MPG is over 11 percent. That is significant savings, and the major difference here is I use AMSOIL and the company trucks use conventional oil!

Both the full flow and by-pass filters are changed regularly, and at each 20,000 mile interval, an oil sample is taken to monitor the oils condition. Currently, I have 412,000 miles on this truck, the last 236,000 without an oil change. The oil analysis from Oil Analyzers, Inc. reports the oil is suitable for continued use and the engine runs great.

Mike Geho
Owner/Operator and AMSOIL Dealer