Current trends in passenger cars are towards higher engine speeds, reduced oil fill volumes, and higher cornering forces, all of which tend to increase levels of oil aeration under dynamic cornering conditions.
For many years CT have been developing the oil aeration and oil handling performance of passenger car engines on a tilt rig under stabilised conditions, followed by validation in vehicle under dynamic conditions. There are currently several devices on the market for on or off-line aeration measurements on the testbed, but in our experience none of these devices are particularly suitable for in-vehicle measurements. The vehicle validation has historically been a subjective assessment, predominantly based on observation of sudden drops in oil pressure. Although an effective Pass/Fail test, little useful information for development of the oil handling is gained.
CT have therefore developed a simple, real time measure of oil aeration in vehicle, based on an accurate correlation of oil aeration level to oil pressure level.