Oils produced for the next generation of low-emissions diesel engines should offer backward compatibility in terms of maintenance practices, but “stricter emission standards don’t mean mineral oils will give way to synthetics,” Mark Nelson, president of ChevronTexaco Global Lubricants, told the Technology & Maintenance Council.
In a speech delivered at the TMC annual meeting in Tampa, Fla., this month, Nelson said that Group II and Group III bases oils can reduce sulfur and that PC-10 – the American Petroleum Institute’s name for the oil standards being developed for the 2007 engines – will offer backward compatibility with earlier oils.
“PC-10 with low sulfur diesel should extend overall maintenance schedules,” Nelson said. “Guidance will emerge from the manufacturers, who are working very hard to develop them.” PC-10 is slated to replace the CI-4 standard. A fleet could use CI-4 in 2007 but their diesel particulate filters might require more cleaning, Nelson said.
Nelson said that low-sulfur diesel is coming online faster than the Environmental Protection Agency mandated but that it will present some challenges to fleets and fuel suppliers. “We concur with the EPA survey that shows 95 percent of fuel will be 15 parts per million (ppm) by mid-2005. We’ll be supplying low sulfur product through our facilities by that time, too,” Nelson said.
But low-sulfur fuel is must more expensive to manufacture, and “studies showing increased fuel usage due to lower energy density are realistic.” Nelson added, however, that engine and vehicle manufacturers are working hard to minimize the impact of that fuel economy impact. Another problem is that lowering the sulfur level removes lubricity, so additives will be needed and there is a potential for over-treatment, he said.
And there are more challenges. Nelson called the handling and distribution of low-sulfur diesel as “the most challenging situation since unleaded gasoline was adopted.” Low-sulfur diesel must be transported by the same facilities that carry other products. During pipeline transfer, there will be sulfur uptake that will depend on the length of the pipeline and other factors. Because of that, the product will be 5 to 10 ppm going into the pipeline. This will be critical for fleets because contaminated fuel will produce higher particulates that will plug particulate filters absent more frequent maintenance intervals.
“In spite of the challenges ahead, trucking’s track record shows that it can adapt and move forward,” Nelson concluded. “We are approaching the 30th anniversary of the catalytic converter’s introduction in the automotive market. If we survived that, we can survive this.”