FYI: The following was copied from the Mobil 1 website...
Question:
Can Mobil 1 Turbo Diesel Truck be Used in a High Compression Car?
I was wondering if Mobil 1 Turbo Diesel Truck 5W-40 is safe to run in a standard American unleaded fuel only V6 DOHC high compression car? 5W-30 does not cut it for my needs and I want to use 5W-40 FULLY
synthetic motor
oil. So my question to you is, Will Mobil 1 Turbo Diesel Truck 5W-40 have any ill effect on the motor I want to use the
oil in? What makes the diesel
oil so special? Does it supersede the oil made for gasoline engines?
-- Rick Speare, Clinton Township, MI
Answer:
Mobil 1 Turbo Diesel Truck is an outstanding oil that can be used in gasoline passenger cars since it carries API SM credentials, so we would not have any concerns about performance. Diesel engine oils generally contain higher levels of detergents, dispersants, and antiwear additives, but keep in mind that higher levels of the ZDDP antiwear additive can be detrimental to catalytic converters and other emission control equipment over time, which is why this additive has been reduced in ILSAC GF-4 oils. Also you will not see optimum fuel economy benefits with diesel type oil.