U.S. Department of Energy FreedomCAR & Vehicle Technologies Program Oil Bypass Filter Technology Evaluation Final Report

This Oil Bypass Filter Technology Evaluation final report documents the feasibility of using oil bypass filters on 17 vehicles in the Idaho National Laboratory (INL) fleet during a 3-year test period. Almost 1.3 million test miles were accumulated, with eleven 4-cycle diesel engine buses accumulating 982,548 test miles and six gasoline-engine Chevrolet Tahoes accumulating 303,172 test miles. Two hundred and forty oil samples, taken at each 12,000-mile bus servicing event and at 3,000 miles for the Tahoes, documented the condition of the engine oils for continued service. Twenty-eight variables were normally tested, including the presence of desired additives and undesired wear metals such as iron and chrome, as well as soot, water, glycol, and fuel. Depending on the assumptions employed, the INL found that oil bypass filter systems for diesel engine buses have a positive payback between 72,000 and 144,000 miles. For the Tahoes, the positive payback was between 66,000 and 69,000 miles.