SAN ANTONIO, Texas — The PC-11 engine oil category has yet to be fully developed, but Shell says it has run enough miles using prototype oils to gain confidence in its performance and fuel-saving potential.
The company has already run 22 million miles with PC-11-type oils and is using the oil in 14 engines that it has been torn down and thoroughly inspected. The longest-running of these was at nearly 800,000 miles when Shell disassembled it for visiting trade press editors during its Global Media Showcase in San Antonio, Texas. Internal parts showed no signs of premature wear or inadequate protection.
“You can run all the engine tests you want in the lab, but the real proof of performance is how that oil is going to work in someone’s engine in their various operating conditions and applications,” explained Matt Urbanak, primary formulator for Shell’s Rotella T product line.
The engine disassembled in Texas belonged to a North Carolina fleet that accumulated about 250,000 miles per year in a team operation. It was a Detroit DD15 engine rated at 475 hp in a Freightliner Cascadia.
The company was using extended 55,000-mile drain intervals and was achieving fuel economy of about 6.3 mpg. The engine was initially run on a CJ-4 oil blended down to a PC-11B viscosity. As the category was further developed, that oil was replaced with a true PC-11B prototype oil. Urbanak said the internal health of the engine after 800,000 miles is giving the company more confidence it will be able to achieve backwards compatibility with the new-generation oils.
He also said Shell’s extensive field testing is helping it gain a competitive advantage.
“It’s our belief that the scope of our global field testing program is unparalleled in the industry,” he said.
While oil analysis is useful for evaluating oil performance and condition, a complete teardown is required to fully understand how well the oil is protecting the engine.
“Oil analysis does not give us a complete picture of how well an oil is protecting the engine,” Urbanak said. “It’s a nice tool but we can’t see the cleanliness of what’s inside the engine.”
One of the greatest challenges facing oil companies is convincing fleets and owner/operators they can achieve fuel savings using a lower viscosity engine oil without compromising on wear protection.
Today’s engines are expected to last a million miles and “obviously the oil is a major contributor to that,” said Dr. Keith Selby, global technical manager, heavy-duty engine oils with Shell.
It has also taken some work to convince customers of the fuel economy gains that can be had by switching to a lower viscosity engine oil. In Europe, 10W-30 and 5W-30 engine oils showed a 1.46% improvement in fuel economy compared to 15W-40s in real-world tests.
Closer to home, North American field trials with Penske and Schneider showed a 1.6% and 1.57% improvement respectively, when moving from 15W-40 to 10W-30 oils.
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