The drive for next-generation auto engine oils
Jean Van Rensselar, Contributing Editor | TLT Feature Article September 2013
For just a little more money, they make a big difference in performance.
KEY CONCEPTS
• Higher-performing engines, government regulation, fuel-efficiency demands and reduced synthetics costs have led to improved auto engine oils.
• Higher quality engine oils are one of the reasons behind the trend toward longer intervals between oil changes.
• New motor oil formulations reduce repairs, prolong engine life and improve fuel efficiency.
If it’s true that you are what you eat, then your car is the oil you put into it. And the continuum of oil quality is ever widening from traditional engine oils (fast food) to ultra-performing synthetics (truffles).
In addition to significantly longer oil change intervals, benefits of new higher-quality oils include longer engine life, fewer repairs and slightly better fuel mileage. Nearly all car owners can take advantage of these new oils since nearly all of these fluids are backward compatible.
Today’s auto engine oils have demands on them that would be beyond the comprehension of an oil formulator even 15 years ago. Among the reasons:
• Engine design: the trend toward higher-performing, more compact engines.
• Fuel efficiency: consumers and regulatory entities are requiring better mileage.
• Demand for longer drain intervals: consumers expect longer drain intervals.
• Environmental concerns: conscientious consumers want to reduce CO2 emissions.
• Relative price: the price differential between mineral-based oils and synthetics is narrowing—which is opening the playing field for high-performance mineral oils.
Steve Haffner, Crankcase Market Manager, Infineum USA L.P. (corporate headquarters in Oxfordshire, England), says, “Over the past 50 years, the automotive, fuel, lubricant and additive industries have undergone significant change. Vehicles must now meet tough fuel economy and emissions regulations but still deliver the excitement, reliability, comfort and sheer pleasure that today’s drivers demand.
“As for today’s fluids, they must not only meet tough specifications but also enable vehicle hardware advances and offer protection to engines that are smaller, have tighter tolerances and that run on a wider portfolio of fuels,” Haffner adds.
SPECIALTY APPLICATIONS
Another reason for new oil formulations is the emerging breed of alternative-fuel cars. All-electric vehicles such as the Nissan Leaf do not use engine oil because the motor’s maintenance-free bearings are sealed for life. But hybrids like the Toyota Prius do have conventional internal-combustion engines that require and use oil just like any other car with a similar engine.
The difference between a conventional car and a hybrid, though, is that hybrid engines turn off and on frequently during use. This creates a significant amount of stress on the engine, which leads to a relatively high amount of harmful deposits. Because of this, hybrids need a highly engineered motor oil that can compensate for these harsh operating conditions.
Natural gas cars use the same type of oil as their conventional counterparts, but the oil tends to degrade in different ways. Because there is no fuel dilution, the oil gets thicker over time. Natural gas engines also tend to run hotter, increasing oxidation rate. A final consideration is that some types of natural gas create acidity. In addition to a specialty oil, periodic oil analysis is almost a necessity.
RE-REFINED MOTOR OIL
It takes about 67 gallons of crude oil to produce one gallon of lubricant basestock, but it only takes 1.6 gallons of used oil to produce the same amount (1). This means there are big environmental benefits to recycling used oil back into basestock.
For a long time, recycling wasn’t very practical, but new technologies capable of producing higher-quality end products at a lower cost are changing that. Newer technologies remove more than just water and basic impurities; they also can remove heavy metals, nitrogen, chlorine and oxygenated compounds. The end product is a basestock that can be recycled over and over. From there the purified basestock is blended with virgin basestock and new additives to make a finished lubricant product that can be just as effective as any other lubricant.
EPA defines re-refined products as containing at least 25 percent re-refined basestock. The California State public contract code defines a re-refined motor oil as containing at least 70 percent re-refined basestock (2).
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GOODBYE 3,000-MILE OIL CHANGE
Today’s longer oil change intervals are due to:
• Improved quality of today’s oils and their ability to protect engines from wear and heat and still deliver good fuel economy with low emissions.
• The fact that more automakers are using synthetic oil.
• Better engineering, including tighter tolerances (the gaps between metal-moving parts) of today’s engines.
• The introduction of oil-life monitoring systems, which notify the driver when an oil change is required and are based on the way the car is driven and the conditions it encounters (3, 4).
Most automakers are specifying oil changes at either 7,500- or 10,000-mile intervals. The longest oil change interval is 15,000 miles for all Jaguar vehicles and some BMWs. Despite this, many consumers aren’t comfortable surpassing the former 3,000 mile/three-month limit. Research shows that in the U.S., 51 percent of vehicle owners still think they should change their oil at the 3,000-mile mark, and only 33 percent go beyond 4,000 miles (5).
The fact that many maintenance facilities, including those specializing in oil changes, continue to promote the old standards, isn’t helping. Even car dealers’ service departments (expected to be aware of oil change intervals for their own vehicles) are guilty of incorrectly listing the mileage for the next oil change. Edmunds reports, “We’ve seen them recommend a 3,000-mile oil change on a car with a 10,000-mile interval and also list a 5,000-mile recommendation on a car that has a variable oil change schedule (6).”
On the surface, this just seems like a waste of money, but there are other downsides to too-frequent oil changes. For example, they create more waste oil that must either be re-refined or dumped somewhere and they also perpetuate dependence on foreign oil.
ENGINE OIL CATEGORIES (7)
Conventional. The fluid is composed of mineral base oils and additives that meet the manufacturer’s specified levels of heat tolerance, breakdown resistance, viscosity and other properties. Conventional motor oil comes in a range of viscosity grades and quality levels, from adequate to ultra high-quality. Conventional motor oil is recommended for drivers with low-mileage, late-model cars whose driving habits can be described as routine.
Synthetic. The base fluid is a precisely controlled laboratory synthesis of ingredients that, when combined with a high-performance additive package, results in an oil with high levels of lubrication and engine protection.
Synthetic Blend. The base fluid is a mix of synthetic and conventional base oils, which provides better resistance to oxidation and better low-temperature properties than conventional oil.
High-mileage. This is blended for older, higher mileage vehicles that are generally out of warranty (typically 75,000 miles and up). It has unique additives and viscosity that help reduce oil burn-off, help seal oil leaks and help improve the combustion chamber seal, which actually helps to restore engine compression.
EXTENDED-LIFE & FILL-FOR-LIFE OILS
Aside from the fact that vehicle manufacturers are continually extending the oil change interval on their cars, engine oil manufacturers are creating oils specifically formulated to extend oil changes. For example, ExxonMobil’s Mobil 1 Extended Performance synthetic oil is good for up to 15,000-miles or one year (whichever occurs first) between changes.
While Mobil says that its Extended Performance oil does not require a special filter or more frequent oil changes (as long as the filter is good quality) (8), this isn’t necessarily the case with other extended life oils. An important point here is that consumers using most extended life oils need to be sure that the filter can also go the distance. Another consideration is that using an extended life oil could potentially void a warranty—not a factor if the car is already out of warranty.
So what’s the likelihood that there will ever be a fill-for-life motor oil? Experts say close to zero. The main reason is that motor oil does a lot more than lubricate. It also helps to control the engine temperature and clean the engine. In fact, cleaning engine components every time the engine fires is an extremely important function of motor oil. Unlike the transmission, the engine doesn’t operate in a closed system. It deals with outside elements (notably water, dust, dirt, pollen, water and engine exhaust) that find their way through the intake and combustion chambers.
Even though some synthetic oils can still provide decent protection when they’re relatively dirty (accounting for the extended oil change interval of synthetics) every oil has its limit. High engine temperatures will cause the oil’s chemical composition to break down over time. For synthetics that time is longer, but no oil is indefinite.
WHAT’S NEW?
The most noteworthy trend is the continuing move toward Group II and Group III basestock globally—made possible by ever-evolving hydrotreating technologies. Haffner says, “The migration away from Group I basestocks continues as demand for premium basestocks rises and production costs fall. This means Group I could account for as little as a third of global capacity by 2017. Future success here will be driven by the profitability of bright stock, waxes and other specialty products.”
Solvent treating as a method for processing base oil has been around since the 1920s and for a long time was the only option. The relatively recent advent of hydroprocessing made a wider selection of crude oils available, some of which yield a higher quality basestock. While Group I basestock had a near monopoly for 80 years, the advent of hydroprocessing allowed Group II and Group III basestocks to contend. In fact, hydroprocessing is now involved in more than 50 percent of finished basestock in North America and is one of the primary catalysts for the changing engine oil landscape.
This hydrotreated basestock has several advantages over its solvent refined counterpart:
• Hydrotreated basestock generally has a higher VI.
• Less carbon residue.
• Lower acid number (AN)—especially important for natural gas vehicles.
• Better demulsibility (water-shedding ability).
• Better oxidation resistance.
• Higher temperature stability.
• Greater purity: Hydrotreated basestock is 99.5 percent pure, while solvent refined basestock is roughly 80 percent pure.
• Better appearance (it is clear and colorless).
This all means that today’s basestock is purer, less volatile, lubricates better on several fronts and lasts longer. This also complicates the rise of pure synthetics, since many of these hydroprocessed basestocks (especially Group II) have properties that are equivalent to synthetics and cost less.
Haffner explains, “The key trend in both heavy-duty and passenger car engine oils is toward lower viscosity for improved fuel economy. Lower HTHS (high temperature, high shear) viscosity and stringent volatility requirements are driving the need for higher viscosity basestocks, including Group II plus, Group III and PAO. The ILSAC GF-5 specification also drives the need for higher viscosity index basestocks to meet basic viscometrics of a conventional ILSAC GF-5 engine oil.”
Group III basestock, processed by hydroisomerization, offers most of the performance advantages of chemically engineered synthetics, but can be manufactured in volumes these synthetics can’t touch. Despite this, there is still a strong and growing market for chemically engineered synthetics for some high-performance autos and in industrial applications such as metalworking fluids.
Raymond Hudack, global strategic marketing manager-lubricants for The Dow Chemical Co., explains, “We will see a continued long-term shift globally toward synthetics and ultra-refined mineral oil basestocks as an enabler for extended drain intervals. From a consumer perspective, the total cost of ownership is lower. This shift will also be highly beneficial for the environment. The European market has already experienced this change compared to North America, which has an entrenched instant oil change industry that reinforces more frequent oil changes.”
New additives also continue to be researched and developed. Haffner explains, “Oils are being formulated to improve fuel economy retention, provide oxidation control at higher operation temperatures and maintain engine protection at lower viscosity.”
“Infineum is always evaluating new additive technologies. As an additive company, we have proprietary components that help lubricants improve fuel economy in a direct manner. But we would rather focus on a holistic approach to the matter, developing additive packages that protect the engine under any operating conditions and at very low oil viscosities that enable fuel economy,” Haffner says. “In many cases, lubricants enable other hardware advances such as start/stop technology, turbocharging, etc. These allow the vehicle to deliver improved fuel economy to the end-user as opposed to just the fuel economy from the lubricant. But we also work with the OEMs to develop oils to enable the hardware to be more fuel-efficient.”
ILSAC GF-6: FOUR KEY PARAMETERS
ILSAC GF-6 is a new auto engine oil category with a first allowable use date of Jan. 1, 2017. The new category calls for improvements in fuel economy and better engine protection than currently exists at lower viscosities. ILSAC GF-6 identifies four parameters based on existing needs:
1.
Better fuel economy that’s maintained throughout the oil change interval.
2.
Enhanced oil robustness for spark-ignited internal combustion engines. This is to ensure acceptable engine oil performance in regional markets due to service requirements, fuel availability, environment issues, etc.
3.
Protection against low-speed pre-ignition (LSPI) in the engine, specifically LSPI attributed to engine oil (9).
4.
Adequate wear protection for engines that are either frequently started or frequently started after extended periods of downtime.
A good example of a new passenger car motor oil formulated to improve fuel economy, meet the demands of new engines, comply with government regulations and reduce emissions is GM’s dexos1™ motor oil. According to GM, the product features the following properties (10):
• Improved viscometric properties that create less friction in the engine, increasing fuel economy.
• Better aeration resistance, which enables fuel-saving devices such as variable valve timing to work optimally.
• Improved oxidation and deposit-forming tendencies, which allow emission systems to operate longer and at their best.
• Better resistance to degradation between oil changes, extending the time and mileage interval between oil changes.
Haffner says, “A challenge for the industry is the rising cost of investment to develop and deliver new lubricants and adequate returns to marketers and additive companies. The next item on the horizon is an upgraded version of GM’s dexos1, which is to the best of our knowledge scheduled for early 2015. In addition to new industry specifications such as ILSAC GF-6, scheduled for Jan. 1, 2017, the industry will formally introduce SAE 0W-16 to the list of engine oil products required in the marketplace coincident with ILSAC GF-6 (11)."
PASSENGER CARS
While anyone who works with fleet vehicles knows the value of regular fluid analysis, many car owners don’t know that there are significant benefits to having their car’s oil regularly tested in a lab, including:
• Advance warning of problems before they necessitate a major repair.
• Assurance that the engine is in good condition before taking a long trip or towing a heavy load.
• A record of diligent maintenance, an advantage when it’s time to sell.
STLE-member Mark Minges, CLS, OMA II, chief operating officer for POLARIS Laboratories, LLC, in Indianapolis, says, “Passenger car oil analysis will detect minor problems before they become major problems and will provide the information necessary to keep the vehicle in top condition. A sequence of regular oil analysis reports is a great way to show a detailed history of the car’s condition when it’s in the process of being sold. In fact, oil analysis has allowed some car dealers to get us much as 15 percent more for the used cars they sell.”
Nearly all cars can benefit from periodic oil analysis. But for some cars, this is more critical. Among the cars that Minges recommends testing are those that the owner plans to keep for more than five years, high-performance cars, high-end cars, collector cars and antique cars.
SAMPLING PROTOCOL
The general protocol for sampling at Analysts, Inc., starts with supplying users with kit materials to capture in-service samples. A sample information form is included with the kit materials and needs to be submitted with the sample. The kit also includes packaging material for shipment to the lab (via a courier or delivery service). No special labeling is required for shipping by ground or air, but the sample container must be sealed, placed into a plastic bag and shipped using either a cardboard or plastic return mailer.
Once the lab receives the sample, it takes 24-48 hours to process it and have a report ready. The report then is mailed, emailed or available for access on the Internet. Reports include an interpretation or diagnosis of the test results, out-of-range data flagged, comments identifying abnormal or critical conditions and recommendations to correct the conditions.
BASESTOCK GROUPS
The American Petroleum Institute (API) categorizes basestocks by their sulfur content, level of saturates and viscosity index (VI). There are five API basestock classifications:
Group I solvent dewaxed basestock is the least refined—usually a mix of different hydrocarbon chains. These oils are generally used in applications without high performance demands but have significant advantages when it comes to additives.
Group II hydroprocessing and refining basestock is common in commercial mineral-based motor oils. They perform acceptably in terms of volatility, oxidative stability and flash/fire points but not as well in terms of cold-start viscosity, extreme pressure durability and pour point. Greater purity means that the basestock and the additives in the finished product will last much longer.
Group III hydroprocessing and refining basestock is the most refined of all mineral oil basestock. It performs well in many regards and is highly stable. Lubricants formulated with this basestock are often synthetic or semisynthetic. Group III basestock is manufactured using the same hydroprocessing techniques as Group II basestock. The difference is that the processes are stepped up in order to yield a higher VI. Today’s Group III basestock performs as well or better than traditional synthetic oils.
Group IV or PAO (polyalphaolefin) basestock is a chemically engineered synthetic. It has a highly stable chemical composition and is increasingly present in synthetic and synthetic-blend products for industrial and vehicle applications.
Group V basestock encompasses all other basestock, including phosphate ester, polyalkylene glycol, silicone and bio-based. It is usually blended with other basestock and used in small amounts as secondary basestock to impart discrete lubricant properties. This basestock is capable of accommodating a wide variety of properties and custom packages. Esters are common Group V basestocks for reasons that include better performance at higher temperatures.
RECOMMENDED TESTS
Bob Broaddus, OMA II, lab manager for Analysts Maintenance Laboratory, Inc., in Hoffman Estates, Ill., cautions that tests should be based on the owner’s objectives, the vehicle type, operating conditions and operating environment. “It’s best to consult with the lab to determine what level of testing is needed to meet objectives,” he says. With that caveat, Broaddus and Minges recommend the following tests:
Spectrochemical/Metal Analysis: measures 21 organometallic elements that include component wear metals from parts such as pistons, rings, cylinders, main or rod bearings, thrust bearings, cam bushings, rocker bushings, camshafts, crankshafts and gear trains, certain contaminants such as dirt and coolant, and elemental oil additives.
Viscosity (at 100 C): determines the SAE grade of the oil. If results fall outside the typical range for a certain grade, it could indicate oxidation, fuel dilution or a mixture of different oils.
Fuel Dilution: high readings indicate that there is a leaking fuel injector or fuel pump.
Oxidation: determines if oil has been in service for extended periods or operating under excessive high heat conditions (how much the oil is oxidizing as it ages).
Nitration: measures whether the engine is tuned and if there is excessive lugging, improper air-to-fuel ratios, air intake or exhaust restrictions.
Water: measures the presence of water.
Glycol: confirms if ethylene or propylene glycol is present (spectrochemical results also can identify coolant additives).
Base Number (BN): measures the amount of alkaline inhibitors remaining in the oil. It also determines optimum oil change intervals and measures how well a product performs. (Minges says this is only needed if the user wants to extend oil drain intervals.)
FREQUENCY
The objectives of the program dictate the frequency of testing. Broaddus recommends taking samples at the first three oil change intervals to establish a trend. After that, intervals can be adjusted depending on the findings of the first few samples.
Minges agrees. “The test frequency is totally dependent on how much the vehicle is driven and how the owner wants to use the information, but fluid analysis is always more valuable when the data is trended over time,” he says.
With even more stringent government demands on OEMs for better fuel efficiency and lower CO2 emissions and consumer demands for better engine performance and fuel efficiency, new better-performing engine oils are a necessity.
Haffner says, “We continue to examine the impacts of the so-called megatrends currently driving change. These include the ever tightening greenhouse gas and tailpipe emissions regulations, calls from consumers and governments for improved fuel economy, fuel and basestock supply and demand imbalances, continued economic instability and the uncertainty about the rate at which some developing markets will mature.”
Oil formulators are currently meeting these demands and aspiring beyond them. Hudack envisions the day when engine oil is tailored to not only each region and OEM but to each vehicle and engine in order to provide maximum fuel-efficiency benefit.
REFERENCES
1. From here.
2. From here.
3. From here.
4. From here. Sixteen of 34 carmakers now use oil-life monitoring systems in their 2013-model year vehicles, including all three domestic automakers. That represents a majority of the vehicles sold in the U.S.
5. From here.
6. From here.
7. From here.
8. From here.
9. LSPI occurs when the combustion chamber ignites prior to the spark. This causes out-of-sync combustion, which can lead to heavy engine knock and severe engine damage.
10. From here.
11. SAE International recently approved SAE 16, which is a lower viscosity alternative to SAE 20 and other non-winter grade engineoils. Its main advantage is that it will lower friction and thus increase fuel economy.
Jean Van Rensselar heads her own communications firm, Smart PR Communications, in Naperville, Ill. You can reach her at jean@smartprcommunications.com.