Friction power measurements with the piston group of a fired gasoline engine

Abstract

In addition to a decrease in exhaust gas emissions, a reduction in frictional losses plays a key role in the ongoing development of the combustion engine. This can further increase mechanical efficiency and reduce fuel consumption accordingly.

In this context, MAHLE has performed systematic tests on fired passenger car and commercial vehicle engines. The tests are focused on the design parameters of the piston group. The knowledge gained can be used specifically to reduce fuel consumption and therefore CO2 emissions in actual engine operation, even at elevated speeds and loads.

The influence on friction of the piston installation clearance, piston pin offset, pin bore geometry (shape and clearance, oil supply), piston skirt geometry (piston skirt contact areas, skirt stiffness, piston profiles), and tangential force of the oil control ring were independently investigated in a turbocharged passenger car gasoline engine. The evaluation took place at warm conditions in the form of the friction mean effective pressure savings potential, which can be converted to savings in CO2 emissions in any desired driving cycle.