Shell Rotella CJ-4 diesel engine oil “gives 50 percent less wear,” according to Dan Arcy, the company’s business-to-business technical marketing manager. “CJ-4 is required for the 2007 engines,” Arcy said at a breakfast event Friday at the Great American Trucking Show in Dallas. “Our CJ-4 goes beyond what is required by the new oil standard.” The new oil is required in order to limit the ash that accumulates in the diesel particulate filter.
“There will be benefits in pre-2007 engines, too,” Arcy said. “Users will see improved deposit control and oxidation stability, among other benefits.” The new oil will be made available in gallon containers Oct. 15.
Arcy said the new oil had to undergo seven new tests to be qualified. “It averaged 50 percent less wear in all areas, including rings, liners, crossheads, bore polish,” Arcy said. “One of the toughest tests was our injector screw and crosshead wear. We got 1,400 points out of 1,400 possible, and the engine maker told us they had never seen anybody’s oil score that high.” The oil’s proprietary detergent system also performed well in terms of the depth and thickness of the sludge in the oil pan, Arcy said.
A critical factor in minimizing the cleaning of the DPF is oil consumption. Arcy said it’s necessary to keep the ring and land areas clean; carbon deposits cause the piston rings to stick, and then you get oil consumption, he said.
Arcy also said that even though the oil will cost 10 to 15 percent more than CI-4 Plus, it’s worth the extra money because of its performance. With a 29 percent reduction in wear metals, it also will help to extend the life of older engines that don’t use a DPF.
TBN, or Total Base Number, is one of the biggest issues of concern with the new oils. Since the oils must have 1 percent or less total ash by weight, most have a reduced TBN. Rotella CJ-4’s TBN dropped from 11.5 to 10.1; however, what the TBN does is counteract the acid formed in combustion. The acid comes primarily from fuel sulfur, which has been reduced from 500 ppm with low-sulfur diesel to only 15 maximum with ULSD. Thus, TBN levels as measured with oil analysis testing actually shows TBN levels are retained at least as well as when running CI-4 Plus and LSD as with CJ-4 and ULSD.
Shell said its refineries will be producing only ULSD. While some of the fuel it sells may have slightly higher levels due to sulfur being picked up in shipping, even higher sulfur-level fuel intended for off-road use still will have only about 20-22 ppm sulfur. Anyone with concerns about sulfur levels should discuss the matter with their fuel supplier, said Arcy.