MONTREAL, Que. — Work continues on a new heavy-duty engine oil category that will provide improved performance with the newest generation engines, beginning in 2016.

Chris Guerrero, Shell Rotella global brand manager, provided Truck News with an update at ExpoCam, pointing out that by the time PC-11 is introduced in 2016, it will have been a full decade since the current CJ-4 category was implemented.

“Every oil category we’ve had throughout time can be tracked to a change in engine design,” he said. “Not every change in engine design requires a new oil. In 2010, we were able to keep it to CJ-4, which is a bit of a testament to over-engineering that product so there was no need to reformulate.”

The new engines being introduced between 2014 and 2017 will offer improved fuel economy and reduced greenhouse gas (GHG) emissions.

“The general consensus is that oil temperatures are going to go up in these new engines,” said Matt Urbanak, Shell HDEO formulator. “As you increase temperature, you’re going to stress oil more. The general rule is for every 10 C increase, you’re going to increase the oxidation rate, so oil is going to break down faster, hence the need for better oxidation stability.”

The PC-11 category is still in the early stages of being developed, but it’s likely to bring improvements in: oxidation stability; shear stability; aeration; and scuffing. There’s also some talk of a biodiesel compatibility test requirement, Guerrero told Truck News.

PC-11 will provide guidelines for traditional 15W-40 oils as well as increasingly popular low-viscosity engine oils.

It’s expected engine manufacturers will continue to push low-viscosity engine oils as a means to meeting new fuel economy targets. Shell has found 10W-30 engine oils can provide notable fuel savings, but those savings range depending on many variables.

“There’s a general acknowledgement from industry that lower-viscosity oils do contribute to better fuel economy,” Guerrero said. “On the Class 8 side, we think that range sits between 1-2%, depending on which fluid you’re dealing with. That’s the range we think with confidence you’d expect to see when using our 10W-30 product versus a typical 15W-40.”

New shear stability requirements to be included in the PC-11 engine oil category should provide some peace of mind for fleet owners who are reticent about using a lighter-weight oil for fear that wear protection could be compromised, Guerrero said.

“We want to make sure when you start out at a 30 weight, that a few thousand kilometres into your driving cycle that you haven’t sheared down into a 20 weight,” he explained.

Delivering improved fuel economy while maintaining existing drain intervals and protection levels is the challenge oil providers face.

“If thinner was the only game, we could just put water in the crankcase and call it a day,” joked Guerrero. “The trick is to make sure we have a product that will not sacrifice in other areas.”

Urbanak noted Shell’s low-viscosity oils are already engineered and proven to provide protection equal to that of 15W-40 oils, as evidenced through engine teardowns at 400,000 miles or more.

The PC-11 category will also push to maintain current drain intervals.

“We’ve seen Detroit Diesel go out with 50,000-mile drain intervals on some of their engines today and I think the key to them is not losing that, not taking a step back even with lower-viscosity engine oils,” Guerrero said.

Cost increases may be inevitable, as low-viscosity engine oils usually require the adoption of synthetic blends, but Guerrero said it’s too early to know for sure. The good news is, the 15W-40 oils that dominate the market today will still be around beyond 2016. And, they’ll be backward-compatible, so customers can take their time warming up to the concept of lighter weight engine oils while those who are eager for the fuel savings will be able to adopt them knowing the new category ensures their performance in areas beyond fuel economy.