Lower Second Ring Tension Reduces Oil Consumption and Friction in Engine Tests: Reducing piston ring tension effectively decreases piston friction but increases oil consumption. Technology to alter this trade-off between piston friction and oil consumption needs to be developed to improve fuel economy without increasing oil consumption. Researchers at Musashi Institute of Technology measured piston friction and oil consumption and observed oil film in the ring pack area in a 0.499-liter, single-cylinder gasoline engine at 2,500 and 3,000 rpm with various BMEP to understand the relationship between piston friction and oil consumption for the effect of piston ring pack tension. A floating liner device was installed on the engine to measure the piston friction. A sulfur tracer technique was used to measure oil consumption in a short time. Fluorescence light in oil containing fluorescent dye was visualized through a glass window installed on the cylinder liner to observe the behavior of oil in the ring pack area.