Major Change in Oil Greatly Reduces Ash Buildup in Engine Filters
Several years ago, Chevron approached a growing problem with the diesel engine particulate filters (DPFs) clogging up on ash created by burned engine oil by stepping out of the box and taking a different look at the additives used in formulating engine lubricants.
The clogging problem, Chevron determined, is being caused by metallic additives (such as calcium, magnesium, zinc, and phosphorus) utilized in formulating engine oil. These particular additives turn to ash during engine combustion. That ash flows into the DPF where it builds up and can only be removed by cleaning the filter. The cost of that cleaning can be $2,000 to $3,000 or greater.
Now, ash buildup in DPFs was expected when such postcombustion emission equipment was added to heavy-duty diesels as part of Tier 4 standards. But the buildup in ash was occurring faster than expected. Engine oil ash is unlike the soot that fuel creates when it is combusted. That soot is “burned off” every time a Tier 4 engine goes through a regeneration cycle.
“We became aware that engine oil ash buildup in DPFs was a growing problem,” explains Shawn Whitacre with Chevron. “But we depend on metallic additives in oil to protect engines.”
Whitacre explains that Chevron’s approach to overcoming the ash buildup problem was to reduce metallic additives. “We did something new and different and got surprisingly good early results.”
Chevron engineers replaced metallic detergents with additives that are low- and no-ash.
Currently, heavy-duty engine oils are formulated with up to 1% sulfated ash. The new oil Chevron has formulated creates just 0.4% sulfated ash.
Dan Holdmeyer of Chevron points out that 75% of engine oil is created from base oil stocks. “Leveraging high-quality base oil was a crucial part of our additive reformulation approach,” he explains.
Not only did this shift in additives dramatically reduce DPF clogging, the new oils extended the life of the oil by “up to 2.5 times plus boosted fuel economy by 3% over the life of the equipment, delivering significant savings to customer,” says James Booth of Chevron.
After extensive testing both by Chevron as well as independent tests by engine makers, Chevron announced the availability of a new heavy-duty diesel oil tabbed Delo 600 ADF. The new oil will be available the first of December in both 15W-40 and 10W-30 formulations.
For more information, go to chevronlubricants.com.