Fuel-Efficient Oils
Automakers are already onto lubricants of lower viscosity, that is, thinner and easier-flowing oils for enhanced mpg. Hyper-milers use these oils, typically replenished to only the lower tick mark of the dipstick, thus minimizing the volume of oil being pumped around. (A questionable frog hair: I'd suspect this short fill would have tradeoffs in startup wear and engine longevity.)
By way of background, an oil's SAE grade is a combination of two numbers; the lower one describing its cold-temperature viscosity; the higher, its viscosity at elevated temperature. A 5w30, for instance, displays 5-weight viscosity (and easy flowing in cold start) at sub-zero temperatures, yet it provides 30-weight viscosity (and hot-running protection) at 100 degrees Celsius/212 degrees Fahrenheit.
Lubricant suppliers have been extending the range of these products. Mobil 1 Advanced Fuel Economy oil, for example, is a premium synthetic available in two grades, 0W-20 and 0W-30. These are claimed to offer as much as a 2-percent benefit in fuel economy, as measured against comparable 5w30 and 10w30 engine oils. By the way, 0W-40 Mobil 1 is already the original-equipment fill in a good number of cars, Porsches among them. Having lower viscosity at high temperature, a 0W-20 or 0w30 would potentially offer even better fuel-economy benefits than a 0W-40.
According to Mobil, these new oils meet or exceed warranty requirements of many cars from Chrysler, Ford, GM, Honda, Mazda, Toyota and other automakers. The 0W-20 grade is recommended in 5W-20 applications; the 0w30 in 5w30 and 10w30 applications. In a sense, each offers enhanced benefits in startup with no sacrifice of protection once underway.
By the way, Mobil specialists dispel as something of a folk legend the notion that modern engines profit from a non-synthetic "break-in" oil. This is corroborated by the many original-equipment Mobil 1 adoptions among automakers. Some applications (turbocharged, for example) have adopted a synthetic for its exemplary performance at high temperature. Others exploit its long-term stability in extending oil-change intervals to 15,000 miles. And adoptions of Energy Conserving oils are evidently in the interest of higher mpg.
It can be noted, by the way, that one advantage of a synthetic base stock is its requiring less viscosity-index improver than what's needed with a conventional petroleum stock to achieve the same "cross-grade" characteristics.
One last comment on synthetics: They're premium products with a premium price. That is, their use may or may not pencil out advantageously compared with less pricey petroleum counterparts. Nevertheless, I consider their other advantages — and the relative cost of a periodic oil change — as good insurance for my automotive investment. I'll accept the claimed 2-percent gain in fuel economy as a welcomed frog hair.
Oil Factoids
Oils are assigned a Service Rating by the American Petroleum Institute based on a series of tests and identified as part of the "donut" of information on the container. (See nearby for a typical one.) However, the latest API Rating, SN, has perhaps been the cause of some misunderstanding. Specifically, this concerns an oil's antiwear additive, typically ZDDP, zinc dialkyldithiophosphate. The lighter SNs, 30-weights and thinner, are low-phosphorous oils formulated to promote long-term durability of converter catalysts, the assumption being that a reduced level of ZDDP is acceptable with metallurgy of today's engines.
Note, though, that heavier SNs, those of 40-weight and beyond, are not subject to this phosphorus limit. These oils are seen as appropriate for engines calling for higher viscosity (and perhaps profiting from a traditional level of antiwear additive).
Another interesting factoid concerns "green" motor oils, those said to be formulated from bio-degradable stocks. In particular, there's a false impression that such oils can be readily tossed out at oil-change time. However, two questions arise: The base stock may be bio-degradable, but what about the additive package? And, much worse, though the original stock may be environmentally friendly, it's certain that the used oil will be contaminated with combustion byproducts, trace metallics and God knows what else. Its disposal requires the same care as that of conventional "non-green" used oils.
http://www.roadandtrack.com/article.asp?section_id=36&article_id=6905&page_number=2
Automakers are already onto lubricants of lower viscosity, that is, thinner and easier-flowing oils for enhanced mpg. Hyper-milers use these oils, typically replenished to only the lower tick mark of the dipstick, thus minimizing the volume of oil being pumped around. (A questionable frog hair: I'd suspect this short fill would have tradeoffs in startup wear and engine longevity.)
By way of background, an oil's SAE grade is a combination of two numbers; the lower one describing its cold-temperature viscosity; the higher, its viscosity at elevated temperature. A 5w30, for instance, displays 5-weight viscosity (and easy flowing in cold start) at sub-zero temperatures, yet it provides 30-weight viscosity (and hot-running protection) at 100 degrees Celsius/212 degrees Fahrenheit.
Lubricant suppliers have been extending the range of these products. Mobil 1 Advanced Fuel Economy oil, for example, is a premium synthetic available in two grades, 0W-20 and 0W-30. These are claimed to offer as much as a 2-percent benefit in fuel economy, as measured against comparable 5w30 and 10w30 engine oils. By the way, 0W-40 Mobil 1 is already the original-equipment fill in a good number of cars, Porsches among them. Having lower viscosity at high temperature, a 0W-20 or 0w30 would potentially offer even better fuel-economy benefits than a 0W-40.
According to Mobil, these new oils meet or exceed warranty requirements of many cars from Chrysler, Ford, GM, Honda, Mazda, Toyota and other automakers. The 0W-20 grade is recommended in 5W-20 applications; the 0w30 in 5w30 and 10w30 applications. In a sense, each offers enhanced benefits in startup with no sacrifice of protection once underway.
By the way, Mobil specialists dispel as something of a folk legend the notion that modern engines profit from a non-synthetic "break-in" oil. This is corroborated by the many original-equipment Mobil 1 adoptions among automakers. Some applications (turbocharged, for example) have adopted a synthetic for its exemplary performance at high temperature. Others exploit its long-term stability in extending oil-change intervals to 15,000 miles. And adoptions of Energy Conserving oils are evidently in the interest of higher mpg.
It can be noted, by the way, that one advantage of a synthetic base stock is its requiring less viscosity-index improver than what's needed with a conventional petroleum stock to achieve the same "cross-grade" characteristics.
One last comment on synthetics: They're premium products with a premium price. That is, their use may or may not pencil out advantageously compared with less pricey petroleum counterparts. Nevertheless, I consider their other advantages — and the relative cost of a periodic oil change — as good insurance for my automotive investment. I'll accept the claimed 2-percent gain in fuel economy as a welcomed frog hair.
Oil Factoids
Oils are assigned a Service Rating by the American Petroleum Institute based on a series of tests and identified as part of the "donut" of information on the container. (See nearby for a typical one.) However, the latest API Rating, SN, has perhaps been the cause of some misunderstanding. Specifically, this concerns an oil's antiwear additive, typically ZDDP, zinc dialkyldithiophosphate. The lighter SNs, 30-weights and thinner, are low-phosphorous oils formulated to promote long-term durability of converter catalysts, the assumption being that a reduced level of ZDDP is acceptable with metallurgy of today's engines.
Note, though, that heavier SNs, those of 40-weight and beyond, are not subject to this phosphorus limit. These oils are seen as appropriate for engines calling for higher viscosity (and perhaps profiting from a traditional level of antiwear additive).
Another interesting factoid concerns "green" motor oils, those said to be formulated from bio-degradable stocks. In particular, there's a false impression that such oils can be readily tossed out at oil-change time. However, two questions arise: The base stock may be bio-degradable, but what about the additive package? And, much worse, though the original stock may be environmentally friendly, it's certain that the used oil will be contaminated with combustion byproducts, trace metallics and God knows what else. Its disposal requires the same care as that of conventional "non-green" used oils.
http://www.roadandtrack.com/article.asp?section_id=36&article_id=6905&page_number=2
