Mack requires CJ-4 oil that also meets its internal specification, Mack EO-O. This is a very low ash lube oil. "The previous oil formulas (CI-4/EO-N) had a high ash content to counter the acid loads encountered with the lube oil as a byproduct of combustion," says McKenna. "This is no longer necessary. With the requirement of the new 15-ppm ULSD fuel to meet the 2007 regulations, the sulfur content has been reduced by some 97%. Therefore, the acid loads will be reduced."
Oil drain intervals are expected to remain unchanged with the CJ-4 oil when used with ULSD fuel. "At Mack, we are increasing the heavy-duty vocational lube oil drain intervals to 300 hours and up to 30,000 highway miles," says McKenna.
Not a big change
The maintenance requirements for the '07 diesel engines have been a major concern for many in the industry. Right now, it appears the concerns were unfounded. There will be some changes and technicians will need to learn the new electrical systems. However, the uptime of the trucks should remain intact.
Of course, there is a cost associated with the new hardware. "The increased cost of this new technology has already been announced by most OEMs in their EPA07 engine escalators," says Dutko. "But serviceability and maintenance issues should hopefully be a non-event for most of our customers."