Oil, changing

It’s not every day that engine lubricants face a new standard. Granted, new multigrade viscosities such as 10W20 are entering the vocabulary, but deep in the chemistry, engine oils are changing in fundamental ways. API SL and GF-3 are addressing new concerns brought about by stricter emission control issues and the need for better energy efficiency.

What’s the driving force behind the new standards? According to the American Petroleum Institute’s Kevin Ferrick, “It’s a complicated process. In the current system, and there are discussions about changing the system, automobile or heavy-duty manufacturers define the need. They will typically submit a draft specification; by that time, they are also proposing the engine tests that will be used to define the category. With any oil category there are two types of tests: bench tests, and engine tests. It’s possible that another group could do it but generally it’s the auto industry, or for diesel, the heavy-duty engine manufacturers.”

Automotive OEM’s have several reasons to adopt new engine lubricants. Emission controls play a significant part, as higher levels of EGR and hotter running engines put pressure on oils to maintain both the physical properties of the fluid (such as viscosity) as well as anti-wear, anti-oxidation and other additive-based benefits carried by the base oil. Fuel efficiency is the other major driver, with U.S. regulations such as Corporate Average Fuel Economy (CAFE), which mandates minimum average fuel consumption across a manufacturer’s product range. With U.S. sales of gas-guzzling sport utilities still strong, even the modest improvement offered by reformulated oils can help a manufacturer avoid costly penalties.

Modern engines are definitely harder on engine oils, according to Jim Arner, manager, technical services for Texaco Lubricants Company (Havoline): “The long term benefits of GF-3 motor oil won’t be immediately noticed by the consumer. You won’t get more RPM’s out of the engine, but you will get better performance over the long term with the new engine designs. The new engines are smaller, run hotter and use more EGR. Part of that gas includes corrosives or compounds that will lead to corrosion in the engine. They also are more subject to sludging and carbonization. They need a dependable detergent package that will last. The other factor is that consumers and OEM’s are looking for longer drain intervals. They need a more robust oil to meet these requirements.”

Why a new standard now?

New standards have been in development for years, and one major factor in their development has been the way oils are tested. The industry uses a series of “Sequence” tests, most of which involve actual automotive engines running on dynamometers. API SJ sequence tests used engines such as the General Motors 5.7 and 3.8 litre pushrod engines, as well as Ford’s 2.3 litre four, none of which is representative of modern high volume passenger car powerplants. The new tests make wider use of modern engines such as the Ford 4.6 litre SOHC V-8 and Nissan’s 2.4 litre four, as well as replacing the engine-based rust test with a new “ball rust” bench test which is consistent and more cost effective. Another new bench test, the TEOST MHT 4, (a thermal engine oil stability test), is also more stringent than the GF-2 version.

From the installer and consumer perspective, the primary reason for using the new oils is that new vehicles demand them for warranty protection, but older engines will also benefit. According to Dr. Clinton Smith, technical advisor, automotive lubricants for Imperial Oil’s Products and Chemicals Division, “The engine manufacturers always want improved fuel economy. Some of the engine manufacturers are struggling there, not so much the Europeans, but primarily the North Americans, so if they can get the lubricant to give them some advantage toward fuel economy, if the engine oil can be more fuel efficient, it helps them meet their CAFE standard. Some of the OEM’s calculate that they can gain a half a mile per gallon. It is an estimate, based on engine test data. The other benefit for the consumer is that the oil is less volatile; its boiling point has been raised. That’s related to how quickly the oil is consumed in the engine. The consumer should experience less oil consumption. Engine manufacturers may take advantage of that to extend drain intervals.”

A corollary benefit for consumers is derived from the previously mentioned tougher TEOST thermal stability test; better engine deposit control. As Smith relates, “The consumer can’t see it, but it’s an improvement that will allow cleaner rings, better engine sealing and reduced oil consumption. You also stay in emission certification longer.”

Yet another improvement in the new oils relates to “oxidation stability”. Oils with poor oxidation properties thicken as they age, and are more likely to form varnish on hot surfaces. GF-3 testing requires superior oxidation stability compared to GF-2. Consumers benefit from easier winter starting, and, like other improvements, it may allow manufacturers to extend drain intervals. An affect noticeable to consumers may be a tendency for the oil to darken more slowly with age. The need to educate consumers to avoid scheduling oil changes based on the colour of the oil will be even greater with GF-3 products. With the obvious benefits of the newer formulations, will longer drain intervals affect consumer awareness of the need for regular oil changes? Jim Arner thinks not: “I don’t think that will do anything. In my opinion, the best way to improve awareness is for leasing companies to enforce scheduled maintenance. Consumers just won’t go out on a Saturday morning for an oil change.”

GF-3, API SL oils have and will receive plenty of attention, much of it through oil company advertising, but a less well known fact about the new standard is that it may be one of the shortest lived in the series. That’s due primarily to the need to cut phosphorus compounds from the formulations in order to prevent poisoning of the catalyst beds in catalytic converters, a problem that promises to become serious as EPA and California standards for emission system durability put added pressure on OEM’s. With tougher emission standards scheduled for 2004, look for GF-4 to arrive in time for the 2004 model year vehicles. GF-4 will be attainable despite the short timeline. Ford and Honda’s 5W-20 oil specifications, for example, already exceed GF-3 standards for oxidation stability, and some manufacturers are demanding deposit control standards that also go beyond the current requirement. Of course, synthetics are an easy route to better properties, but with the exception of a few high-performance models, manufacturers have balked at the cost. And cost will continue to be a limiting factor in how good mass-market engine oils will evolve. With Canadian consumers often paying more for a litre of bottled water than for the same quantity of highly engineered engine lubricant, protecting the second biggest investment in most Canadian households is still a matter of selling prevention against the bargain-basement mentality. GF-3 oils will cost a little more, but as Texaco’s Jim Arner says simply, “GF-3 oils much better for engines.” SSGM