Technical Paper
Formulation Effects in a Severe Passenger Car Diesel Engine Test
2002-10-21
2002-01-2678
The CEC-L-78-T-99 test, also known as the VW PV 1452 procedure, is a severe test of a lubricant's ability to prevent piston deposits and ring stick in a passenger car diesel engine. The test features in the ACEA “B” sequences and also, at a somewhat higher performance level, in various proprietary specifications. The demanding nature of the test means that it exerts a major influence upon the formulation of lubricants meeting these performance standards. Passing this test with the SAE 5W-30 or 0W-30 grade oils needed for fuel economy can be a difficult task and obtaining satisfactory results from statistically designed experimentation can be plagued by instances of ring stick. A modified test procedure has been developed with the intention of avoiding the loss of data due to ring sticking. By stopping the test at intervals during the procedure, intermediate piston ratings can be obtained, this does not affect the outcome of the test.