CI-4 PLUS?
As they develop the new PC-10 oils, lubricant manufacturers want to avoid what happened with CI-4 oils: When the new engines actually hit the road, the oil category did not perform as well as hoped in some engines.
"One of the significant challenges in developing CI-4 oils was that the development of the '02 engine hardware was running parallel with the development of the engine oils," says Mark Betner, heavy duty product manager for CITGO Petroleum Corp. In some cases, the engines didn't come out until after the oils.
"Even though the development of CI-4 technology was claimed to have been one of the best efforts ever in bringing a relevant and high quality performance classification to the market, it was virtually impossible to test and work out all of the issues facing the various engine builders," Betner says. "Consequently, we had 'aftermath' developments in '03, which led to some new specifications."
Within five months of CI-4 being completed and developed, we saw the first engine manufacturer specification requiring performance beyond the CI-4 standard, according to Lubrizol's Tom Weyenberg.
Among other things, higher soot did not materialize across the board as predicted. Some '02 engines are putting more soot into the oil, but other new engines actually have shown reduced soot loading.
According to Dave Taber, technical coordinator for heavy duty engine oils at ConocoPhillips, Mack has seen some problems with viscosity increase in field fleets using the new CI-4 oils — the oil gets too thick because of the amount of soot in it. As a result, Mack developed a new spec, Mack EO-N Premium Plus 03. Oils can be marketed as meeting this spec if they pass a Mack engine test that simulates high soot loading.
Additional OEM specifications for oil are nothing new; Mack, for instance, has had its EO spec for some time. But because engine makers are using different technologies to meet the new emissions requirements, some of the specs contradict each other. While Mack wants a higher TBN number to handle the soot, for instance, higher TBN typically means more sulfated ash — and Caterpillar's new ECF-1 spec will not endorse oils with more than 1.5% of the ash.
It's this Caterpillar spec that has caused some consternation, according to Taber. Unlike other specs, it is an arbitrary chemical limit, rather than an engine test that would check to see if the oil in question was causing piston deposits. That is the concern Caterpillar has with the ash in its ACERT engines. At press time, Caterpillar reportedly was developing such a test.
All the additional tests — about half a dozen altogether — may be combined into an unprecedented interim oil category, sort of a "CI-4 Plus."
Weyenberg predicts that a new supplement to the CI-4 category will be defined between the middle and the end of this year. There's no process in place for this type of supplemental category, but it's possible that a supplemental designation, such as "US04," could be placed in the bottom of the API CI-4 "donut."
This supplemental category is being discussed even as the industry works on the next category of oils to lubricate 2007 engines.
"In light of this learning experience, one of the key challenges for '07 oils will be to get complete performance data on all engine designs prior to releasing the next generation of heavy duty engine oils," Betner says.
