New Four-stroke Diesel Engine Oil Standards for Japanese Market: JASO DH-2 and DL-1

This paper reviews the development of the new four-stroke diesel engine oil standards, JASO DH-2 and DL-1 (JASO M335-05) for Japanese automotive diesel engines equipped with after treatment devices, e.g. Diesel Particulate Filter (DPF) to meet the new long-term emissions regulations. These standards have been introduced in Japan in April 2005. The standards prescribe the minimum performance for engine oils conforming to Japan-made four-stroke diesel engines with aftertreatment devices using low sulfur diesel fuel (less than or equal to 0.005 mass % sulfur).

The engine test requirements for these new standards are basically the same as those of the JASO DH-1 automotive diesel engine oil standard (JASO M-355 2000) to meet engine oil performances with soot dispersancy (ASTM D 5967-99), piston detergency (JASO M336-98), thermal and oxidation stability (ASTM Seq. IIIE and IIIF), and anti-wear performance (JASO M354-99). The specified bench tests measure hot surface deposit control, anti-foaming, volatility, anti-corrosion, shear-stability, base number, and seal compatibility. Limits for chemical elements and sulfated ash are newly set to protect aftertreatment devices.