N ORDER TO TEST THE PERFORMANCE capabilities of AMSOIL Synthetic 15W-40 Heavy Duty Diesel and Marine Oil (AME), AMSOIL sought a partner with a fleet that operated in truly severe conditions. The perfect match was found in Duluth, Minn.-based Nordic Waste. Nordic Waste operates a fleet of 10 International refuse haulers, providing trash and recycling pickup to residential and commercial customers in the greater Duluth/ Superior, WS region. Nordic's trucks operate in the bitter cold of sub-zero winters, as well as on humid summer days that can top out at over 90ºF. The fleet runs 12 hours a day with frequent stops and redlined starts, all while hauling up to 22,000 lbs. of refuse and navigating the seriously steep hills of Duluth.

As if the geographic challenges aren't enough, perhaps the greatest strain a refuse hauler's engine faces is dumping the refuse. This action requires the engine to remain near or above redline throughout the process and shakes the truck enough to nearly lift the front tires off the ground. Nordic's trucks dump their contents twice daily, challenging the oil's shear stability on a regular basis.

The truck used in this study is a 2006 International 7400 rear-loading refuse hauler. This particular truck was chosen because its Navistar DT466 engine employs a hydraulically-actuated, electronically-controlled unit injector (HEUI) that uses engine oil pressure to inject diesel fuel into the combustion chamber. HEUI systems feature a variable pump (in addition to the oil pump) that pressurizes the oil according to the fuel injection system's needs, placing a considerable amount of additional strain on engine oil. HEUI systems can raise oil pressure to as high as 3,500 psi, creating great potential for shearing and adding signifi cant stress to motor oil that is already operating in a severe environment. The HEUI system's reputation for shearing less robust motor oils made the DT466 engine the perfect choice for testing the durability of AMSOIL Heavy Duty Diesel and Marine Oil.

983-Hour Drain Interval
Nordic Waste initially installed Shell Rotella T 15W-40 Motor Oil (239 hours). AMSOIL Synthetic 15W-40 Diesel and Marine Oil was installed for the subsequent service interval and monitored via oil analysis. AMSOIL Diesel and Marine Oil provided 983 hours of service before oil analysis indicated it was time to drain the oil. As expected, the results revealed that AMSOIL Diesel Oil contained wear metals well below International's published condemnation limits, even after nearly 1,000 hours of service.

Routine Teardown
At approximately 8,000 hours of use, Nordic Waste brought its International 7400 refuse hauler to a certified International Truck mechanic for a routine teardown. The engine was virtually free of deposits, displayed minimal wear and received high praise from the mechanic who performed the inspection.

Use of AMSOIL Diesel Oil Saves Money
Nordic Waste saves a considerable amount of money just by using AMSOIL Synthetic Diesel and Marine Oil rather than a conventional petroleum product. The company has used inferior products in the past, and its search for a high performance lubricant that could withstand the punishment its fleet delivered led it to AMSOIL.

"With the big hills, high heat and extreme cold we work in, nothing has performed better," said Nordic Waste Owner Brian Johnson. Prior to discovering AMSOIL, the conventional lubricants Nordic used would shear out of viscosity- grade rapidly and need to be changed at approximately 200 hours of service. Upon switching to AMSOIL Synthetic 15W-40 Diesel and Marine Oil, Nordic Waste increased the average drain interval for its trucks from approximately 200 hours to nearly 1,000 hours. In addition, Nordic's use of AMSOIL Diesel Oil means the company's trucks are well-protected and run at optimum fuel economy, so they stay out of the shop and on the road.

"We experience less downtime and have seen reductions in costs associated with engine overhauls and replacement parts," said Johnson. "We buy significantly less oil, fewer fi lters and we experience lower labor costs. Our biggest savings have been the reduced number of engine overhauls and replacement parts."

Use of AMSOIL Synthetic 15W-40 Diesel and Marine Oil saves Nordic Waste thousands of dollars in oil alone, in addition to reduced expenses for labor, filters and waste oil and used filter disposal.