PM Dilemma?

Is CJ-4 engine oil tough enough for vocational duty cycles?


If you're looking for someone to blame for the added cost of the new standard, the lubricant companies will point the finger at the required testing measures. Citgo's Betner explains the differences in the pricing between petroleum-based products—just because gas prices have recently dropped, it doesn't mean your oil is going to cost you less in 2007:

" Fuel and gasoline so often gets attached to lubricants, and really, they're different animals. I think the reasons that need to be communicated (behind the CJ-4 price premium) are not just your to everyday oil perceptions," Betner says. " Not only do you have a lot of chemicals in lubricants, you have extreme levels of testing requirements that you don't even have near involved with fuels. If you think back to 1972, we could license a heavy duty engine oil for about 1.5 million dollars. Today it's going to be well over 30 million dollars—possibly we'll top over 50 million before it's all said and done."

Shell dealt with the same, expensive regimen, but Arcy is quick to point out that the numbers don't lie about the quality of the new product line. " There was a lot of cost in the testing that had to go into the development of these new products. Some of the tests you have to run are pretty substantial tests," he explains.

" If you take the average (laboratory) wear test, we saw a 50 percent reduction in wear with the CJ-4 product over the CI-4 Plus product. That would be one of the reasons you'd want to go to it, even though you may not have a 2007 engine," Arcy adds. " What we've seen in the on-highway testing of this product is upwards of 38 percent reduction in wear versus CI-4 Plus."


That rigorous testing pays big dividends for medium-duty fleets, according to Jim McGeehan, global manager, diesel engine oil technology for Chevron Products Company.

"All the tests we run (on CJ-4) are more severe than the tests we run on CI-4 Plus," McGeehan says. " Demands in light and medium-duty fleets can be more severe than in line-haul fleets. A line-haul truck stays at a constant speed normally, whereas the vocational vehicle goes through these cycles of idle to full power to stop-and-go. Because of that you can get more soot in the engine oil, which we need to disperse in terms of preventing viscosity increase. We have to ensure that it doesn't cause any wear during this cycling.

"There's a new test in this category, called the Cummins ISB, which develops a relatively high soot amount in the oil—three and a half percent—then for the next 300 hours it cycles 32,000 times," McGeehan explains. " That's going from idle to full power to peak torque, and it does this to put stress on the cam system and the follower. The turbocharger can hardly keep up with it; it's a very severe test. And it reminds me of a vocational vehicle, where there's a lot more stop-and-go issues going on, a lot more cycling going on. So, from that point of view, I think CJ-4 will perform equal to or better than CI-4 Plus, because of the severity of some of the new tests. It will definitely give medium-duty fleets the same protection they've always had, and hopefully some enhanced protection.

"We also have the Cummins ISM, which is a test for what we call cross-head wear," he continues. " You have four valves—two intake, two exhaust—and there's a crosslink that the rocker arm hits and presses them down. Then there's an injector screw, which sets the injector time and position. In this test, in terms of wear, you have to protect the overhead system from wear and the injector screw from wear, with a high soot level; six and a half percent soot in the oil.

"Beyond that, we have a Mack T-12 test that mainly looks at bearing wear control under high oxidation conditions," he says. "So, there are three particular wear tests that the CJ-4 oils have to go through, so I do not see an issue if the oils clearly pass CJ-4. We should actually have better protection than the previous oils."

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