Smaller, More Powerful Engines Means New Oil Specs

Small, more power vehicle engines and people’s willingness to hold onto vehicles longer are causing changes in motor oil formulations.

According to the industry information group Edmonds.com, nearly half of all vehicles sold in North America are built around four-cylinder engines. Work is currently underway by such heavyweight players as BMW, Volkswagen and Nissan to have engines that can get high mileage and produce the power of what was traditionally seen in muscle cars using only three cylinders. The move to such smaller engines is being driven, particularly in the United States, to meet new fuel economy and emissions standards that will require vehicles to meet an average 6.9 litres per 100 km by 2016 and 4.31 litres per 100 km by 2025.

These smaller engines put new stresses on the motor oils, said Oliver Kuhn, a researcher in the research and development department of German-based Liqui Moly. To get the same performance despite reduced cubic capacity, the engine needs to be operated at higher RPM, the oil capacity of downsized engines is reduced by 30-40 per cent, but circulates more often and must be able to deliver on the improved performance demanded by the engine; and though the oil temperature remains the same, due to the accelerated circulation within the engine, the motor oil gets no ‘rests’ to cool down a bit, added Kuhn.

“These factors lead to an accelerated aging of the oil,” he continued. “So motor oil for downsized engines must be able to withstand permanent high stress, must be ageing resistant and must deliver extra wear protection.”

Jeff Hsu, global PCMO, Delivery Team with Quaker State said he understands these engine stresses as his research is on developing oil formulation for gasoline direct injection engines. Unlike traditional fuel injection systems, GDI engines offer more precise fuel metering and injection timing, and a more optimal spray pattern that result in a more efficient burn of the fuel while producing less harmful emissions.

The downside is because the fuel is sprayed directly into the cylinder bore and the atomization of the fuel occurs in the upper stream, “this fuel has a tendency to get by the rings and cause more oxidation and oil degradation.”

All this means a greater emphasis and more research dollars and hours spent on developing oils that can survive in these high-stress engine environments without any loss of protection and lubrication ability, all the while helping maintain the components, seals and systems.

“To meet these engine challenges, the lubricant industry in North America has moved to motor oils that meet both ILSAC GF-5 and API SN categories,” said Heather Burkett, marketing manager, lubricants and specialties, Imperial Oil. “This category upgrade offers enhanced oil performance, as evidenced by better engine protection from sludge formation, improved piston cleanliness, while at the same time offering improved fuel economy and enhanced emissions system durability.”

What is vitally important is the additive packages used. These deliver the protection and durability needed to survive in today’s new engines, and help the oil meet the industry-agreed upon ILSAC and API specifications used by all of the oil blenders in North America. Chris Hayek, Quaker State global brand manger said the emphasis is on making sure motor oils, “are good from the start right to the end” which is why the additive packages are so critical for vehicle owners to get educated on.

You can’t just go ahead and pour any motor oil close-at-hand into an engine. That is a recipe for trouble.

“Mineral or partly synthetic oil are not able to deliver the performance needed to downsized engines,” added Liqui Moly’s Kuhn. “Using such oils results in increased wear and collapsing oil well before the oil change is due. The more performance is demanded from the motor oil, the more important are the additive packages.”

Kuhn sees two trends emerging in motor oil blending. The first is that advancements in engine technologies will make motor oils very thin. The purpose of this lower viscosity is to further reduce the inner drag of the motor oil. While thin motor oil would seem to invite metal-to-metal contact, new additive packages will likely keep this from happening. As well, new motor oils will be blended to meet specific engine requirements outlined by vehicle manufacturers. “This already took place during the past decades when several mostly European car manufacturers were not satisfied with the industrial oil standards (and) issued their own oil specifications, like Volkswagen, Mercedes, BMW and Porsche, just to name a few. One universal motor oil fitting all cars, this belongs to the past.”

One thing to keep in mind is that while new engine technologies are something to keep abreast of, one should never forget that more people are holding onto their cars much longer. Studies looking at vehicle ownership in Canada and the United States find most people are on average holding onto their vehicles for 10 years and longer before considering the purchase of a new vehicle. Part of that is driven by economics; another reason is vehicles are being better built. As vehicles age, however, they require more maintenance. Public research firms such as Ipsos Reid and industry studies by J.D. Power and Associates find as the kilometres increase vehicles go into the shop more often for maintenance and repair. Motor oils for high-mileage vehicles must become part of the maintenance routine. These oils feature additives that have such things as seal conditioning agents and preventive wear formulations.

“Regular oil changes according to the car manufacturer’s instructions are crucial for older cars, too,” added Khun. “Of course, there are stories about cars running for tens of thousands of kilometres on the same oil without any obvious problems. But when an engine is damaged due to skipped oil changes, people tend not to spread this news. And even the cars successfully running on the same oil for a very long time may carry a ticking time bomb in their engine. Though everything is working ok at the moment, the excessive wear and tear will take their toll, engine failures are more likely to occur and the engine’s lifetime is shortened.”