Offering test results that show significant wear and deposit-control advances for the new CJ-4 Rotella T oil developed for 2007-spec diesel engines, Shell Lubricants has announced that it will also continue offering CI-4 Plus oils for older engines. In addition to the performance advantages, the new oil formulation is backward-compatible with all older diesel engines, but will also carry a price premium, company officials said at a press launch for its new CJ-4 Rotella T.
Targeted at small- to medium-fleet users, as well as owner-operators, the new Rotella T was made available in bulk and drum quantities on July 1. Quart, gallon and pail quantities won't be on the market until Oct. 15, which is the first day the American Petroleum Institute (API) will allow its CJ-4 specification “donut” label to appear on packaging. The older CI-4 Plus Rotella T will only be sold in bulk and drum quantities as of Oct. 15.
Shell's large-fleet brand Rimula is also being offered in both API classifications, the CJ-4 Rimula Super and CI-4 Plus Rimula Premium. Again, the new spec version became available in bulk and drum quantities on July 1 and will be offered in jugs on Oct. 15. The older formulation will be offered in bulk quantities only.
In addition to meeting the API's CJ-4 specifications, Shell's 2007-spec oils have already been certified as meeting additional engine-manufacturer oil requirements from Caterpillar, Cummins, Mack and Volvo, as well as draft spec requirements from Detroit Diesel.
The new Shell oils required the most significant chemistry changes in almost 30 years, according to Dan Arcy, technical marketing manager, Transport Lubricants. In particular, they have to be able to handle higher operating temperatures and soot levels in 2007 low-emissions diesels, he said.
Engine wear tests conducted by Shell show the new oil providing on average 50% greater wear protection, according to Arcy. Those laboratory tests were backed by 5.5-million miles of on-highway testing that also showed “significantly lower iron wear,” he said at the Shell press event. Reduced wear in valve adjuster screws alone could potentially offset the oil's premium cost by reducing valve adjustment requirements, Arcy pointed out.
A 30% reduction in ash content for the new CJ-4 formulation, combined with a new detergent system, should also provide better control of high-temperature piston deposits, as well as help optimize the durability and performance of the diesel particulate filters (DPFs) used with 2007-spec diesels.
Although fleets can choose to continue using older oils in pre-2007 engines, “they must use CJ-4 in the new ones” to avoid plugging aftertreatment systems with soot and perhaps voiding warranties, he said.
Preparing bulk storage tanks for the new oil requires draining them completely “and cleaning them if at all possible” before refilling with CJ-4, Arcy said. He also pointed out that blending used motor oil with diesel fuel would “no longer be acceptable with the new engines.”