ASTM's Development of the Sequence VI Fuel Efficient Engine Oil Dynamometer Test

An ASTM task force has completed development of an engine dynamometer test for measuring the ability of engine oils to improve fuel economy in passenger cars and light-duty trucks. The test was designed to correlate with its predecessor 5-Car chassis dynamometer test. Initial development utilized a 2.3L four-cylinder engine. After several operating modes were evaluated, a steady-state, constant output test regime was adopted. Ultimately, a 3.8L V-6 engine was selected. The test Incorporates engine calibration of both viscosity and friction modification responsiveness prior to each test. Blind reference oil evaluations further validate the test calibration. These features have enabled repeatability and reproducibility of this 65-hour test to equal that of the mote expansive 5-Car method. Correlation with the 5-Car test is excellent. The test is considered useful for defining both EC and the tentative EC-1 performance categories of energy-conserving oils.