Fuel efficiency isn't all about hardware - Lubricant additive technology has a part to play
High fuel costs, a desire for improved security of energy supply and the need to reduce emissions of substances considered to be harmful to the environment mean governments around the globe are looking to improve fuel efficiency in the transport sector. While OEMs focus on hardware developments to help maximize the fuel efficiency of their vehicles perhaps the time has come to re-examine how lubricants & related accessories can play their part in the quest for improved fuel economy.
Lubricant solutions - The drive for reduced emissions, principally through better fuel economy, is accompanied by a need for better engine cleanliness, greater durability, and longer service and oil drain intervals. For improved fuel economy lubricants with lower viscosities and additives that provide long term retention of fuel economy benefits are needed. However, for improved antiwear protection careful consideration of lubricant viscometrics and a different additive balance are required. Light-duty diesels need highly dispersant lubricants to handle high soot levels, while extended drain requires good detergency and antioxidant behaviour. The formulation of lubricants to meet all these complex needs can result in some level of compromise.
The recent focus in ILSAC GF-5 and other standards on improved fuel economy & fuel economy retention must come hand in hand with engine oil robustness and the protection of engine hardware and emission control systems. We believe that ILSAC & ACEA specifications should provide a core set of performance requirements defining oils which will run in current vehicles without causing any problems. The resulting oils may give modest fuel economy improvements and will be a cost effective, safe foundation level on top of which OEMs can build additional specifications for improved performance.
More significant improvements in fuel economy may be possible by tailoring lubricant & additive solutions for individual engine types & OEMs, which could be a way to help meet future CO2 emission and fuel efficiency targets. One challenge for the industry to ponder is: do the current specification systems and testing protocols provide the right mechanisms and incentives to lead to optimum fuel economy contribution from the lubricant?
Increase oil lubricity to increase fuel economy! Reducing friction in motor oil is undoubtedly a powerful way in reducing fuel consumption, and this has been a major factor in car makers' shift of recommending oils from the older high-viscosity (20W-50, 10W-30) to the newer low-viscosity (0W-20). ENEOS Motor Oil is the most environmental due to:
- lowest viscosity as recommended by car makers,
- blended with friction reducers,
- extended oil change intervals.
Oil change intervals will depend on your driving habit and type of vehicle. If you do a lot of "hard", city or low speed / low frequency driving, we recommend oil changes at the safe 3,000 miles interval provided that you use US oil (non-synthetic). ENEOS motor oil can last a minimum of 10,000 miles, but due to engine containments and byproducts, we recommend a more frequent change interval for optimal protection. Vehicles that are driven more lightly, or see the majority of highway driving may go to 15,000 miles plus intervals. We still suggest a routine check up of the condition of the oil every 3,000 to 5,000 miles or so to ensure optimal protection, or better yet, use the real-time oil quality monitoring system called: IntelliStick to eliminate all unnecessary oil changes. In Europe, it is common practice to change engine oil after 10,000 miles, or in some cases as much as 15,000. Strangely, in the US it seems normal to change at 3,000 miles. Please also upgrade / upsize your oil & air filters when using high quality oil for optimal results.
Upsize oil filter. Small stock oil filters run with quite a high back pressure and the bypass valve is engineered to trip at about 3,500 RPM, once it trips, your oil is no longer being filtered. Tripping also happens as your oil filter starts to clog up. Please note: Bigger filter = lower back pressure = higher RPM threshold for the bypass valve to trip = less engine power loss in the filter. Bigger filter = better filtering & more power at low to mid revs. Bigger filter = more oil = less stress on the oil.
Upgrade oil filter. 2 methods to achieve this: Use oil filters with higher filtration capacity like the AMSOil Ea and/or use magnets like FilterMAG to take detrimental metallic particles out of circulation. Last but not least, did you know that TruFilter is a washable/reusable oil filter that lasts as long as your car?
Upgrade air filter. What does air filter have anything to do with oil change? A typical engine pumps about 10,000 liters of air for every liter of fuel consumed, and along with all that air being sucked in is plenty of dirt & grit. A good air filter stops everything bigger than a micron in diameter - anything smaller mostly just floats around harmlessly in the 0.001" minimum thickness of oil films that separate all the moving parts. Despite of this, there will always be submicronic particles that get in & gather somewhere in the engine oilways. Every time you empty the oil from your sump, you're also draining this fine grit with it. So now do you see the relation & benefits of upgrading your air filter as well? See AMSOil Air Filter page.
Never overfill your engine with oil! The problem with this is that next time the engine runs, the windage in the crankcase and other pressures generated by the oil pump, etc. place a great strain on the seal on the rear main bearing. Eventually, the rear main bearing seal ruptures, and the engine leaks oil into the bearings, excess oil gets thrown up into the piston bores where the piston rings have a hard time coping with the excess oil & pressure. Then it gets into the combustion chamber and some of it will get out into the exhaust system to ruin the platinum surfaces of your catalytic converter, which will be rendered useless, for good. In short, exceeding the recommended engine oil levels can result in significant oil churning/spin losses. The effects of these excessive churning/spin losses (greater than 2% impact on economy) include the following:
- Reduced engine efficiency
- Reduction in performance
- Deterioration of critical oil properties (lubrication and heat transfer)
Full Synthetic or Mineral Base? Synthetic base lubricants are manufactured in the laboratory to exhibit superior high temperature stability and low temperature fluidity. Since these fluids are created to exhibit less thickening at low temperatures, pumping losses are reduced and substantial reductions in spin losses can be realised at low operating temperatures. All oils thicken at low temperature, causing increased fuel consumption. The synthetic oil is less affected by temperature. This makes synthetic oils more fuel efficient at lower ambient temperatures.
Effects of Lubricant Temperature and Performance
Synthetic 0W-20 for Hybrids? Absolutely! Toyota has started to recommend 0W-20 motor oils for their current & future hybrids. Apart from the obvious positive fuel-saving aspect of 0W-20 oils as mentioned above, the main reason being the way that their HSD (Hybrid Synergy Drive) works. HSD switches back & forth between ICE (internal combustion engine) & electric engine. Every time it switches off the ICE, the oil cools down, and when activated again, it's a cold start (bad MPG) all over. Toyota even tries to remedy this by keeping a few quarts of coolant heated constantly so at every switch over, it dumps hot coolant into the system to warm up the engine. Having a very low viscosity 0W-20 in there allows maximum protection & quicker warming every time. As a side note, ENEOS' 0W-20 has been extensively tested in 5.7L V8 engines in hot Arizonian temperatures and passed with flying colors, it definitely offers more than enough protection for the Prius & other hybrids.
No oil additives! They're absolutely unnecessary & in some cases, will impair your oil's anti-wear properties. All necessary, beneficial & chemically-compatible additives are already included in your motor oil formula. Don't blindly add other companies' unapproved products & hope that they will enhance your oil quality. Oil companies like Nippon spend hundreds of millions on R&D so please don't ruin their golden formula with some iffy stuff!
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