In order to demonstrate the effectiveness of AMSOIL 15W-40 Synthetic Heavy Duty Diesel and Marine Motor Oil and the AMSOIL Dual-Gard filtration system in reducing operating expenses, AMSOIL and Direct Dealer Bill Andes began an ongoing field test in October 1998 with the bus fleet of the Clark County Board of Mental Retardation & Developmental Disabilities (MR/DD) in Springfield, Ohio. Participating in the field test are three 1997 International 3800 school buses, two equipped with International 466 diesel engines and one with an International 466E diesel engine. Each had previously been running a conventional petroleum-based oil.

Prior to starting the field test, four goals were set:

Baseline samples of the petroleum oil already in the crankcase were obtained, tested and documented. Next, the oil was drained and the engines flushed with AMSOIL Engine Flush. AMSOIL BMK-12 Filter Mounts, two BE-110 By-pass Filtration elements and AMSOIL 15W-40 Synthetic Heavy Duty Diesel and Marine Motor Oil were installed in each vehicle.

Oil samples from each bus are drawn and tested at 4000-mile intervals, the normal oil drain interval practiced by MR/DD when using conventional lubricants. Data obtained from the oil samples serves to determine the following:

Once drawn, each oil sample is reviewed in the areas of elemental analysis (including wear metals, contaminates and additives), physical properties (including viscosity, total acid number and total base number) and contamination (including water, solids, glycol, oxidation, fuel soot and fuel dilution). Oil condemnation limits vary due to individual engine idiosyncrasies, operating conditions and time the fluid has been in service.

Observations
As of May 1, 2001, the buses had accumulated a total of 182,426 miles without oil changes, and several benefits associated with running the AMSOIL products have been realized. First, both labor and vehicle downtime have been reduced. While using the previous petroleum-based motor oil, the Clark County Board of MR/DD was accustomed to changing oil at 4,000-mile intervals. They now plan to extend their intervals to 10,000 miles and beyond if supported by oil analysis results. The chart below shows the comparison figures.

As for the aftermarket full flow oil filters, the original intention was to change them every 6,000 to 10,000 miles, but after careful review of oil analysis results, it was determined that because of the efficiency of the AMSOIL Dual-Gard filtration system, 10,000- to 12,000-mile intervals were easily obtainable on the full-flow filters.

For demonstration purposes, the BE-110 filter elements remained unchanged for a 2-year period. However, after review, it was deter-mined that under normal conditions it would be beneficial to change them after a 40,000- to 50,000-mile interval.

Engine wear rates have decreased significantly since changing to AMSOIL 15W-40 Synthetic Heavy Duty Diesel and Marine Motor Oil. High temperature operating conditions have also been reduced. This leads to enhanced engine protection, and ultimately, to longer engine life. Because the engines have been operating more efficiently, three to five percent gains in fuel economy have also been realized. The chart below compares the levels of wear particles present in the previous conventional oil with the levels present in the AMSOIL as of May 2001. The condition of the AMSOIL at various testing intervals is documented below.

Conclusion
Overall, this field demonstration was highly successful for AMSOIL. The oil analysis data indicate that AMSOIL products deliver uncompromising protection and performance. AMSOIL pro-vides longer equipment life and reduced downtime, longer drain intervals, significant decreases in wear rates and operating temperatures and dramatic improvement in engine performance when compared to conventional petroleum oils.