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And accidentally refilling with another oil that costs less could end up costing you big; using a different oil could void your warranty. It's no doubt something that every mechanic is aware of, but if yours isn't used to working on newer cars, it might pay to provide a reminder.
According to Automotive News, all 2011 General Motors vehicles are being filled with next-generation motor oils that promises both higher fuel-efficiency and lower wear. The new oils—called GF-5, SN, or Dexos1—are being phased in this month and officially replace GF-4 and SM motor oils.
The new oils will allow longer oil-change intervals as well, thanks to engineering changes that have been made together with the new standard—which has been in the works since 2006—including larger oil pans, more aluminum in engines, and oil-life-monitoring systems, which calculate intervals with data from driving style and other conditions.
Ford is now specifying oil-change intervals of up to 10,000 miles with the new oil, while GM is relying entirely on driving conditions and its oil-monitor system.
Dexos1 is a proprietary GM oil that's tested to slightly different standards, though some oils already on the market—Pennzoil Platinum and Quaker State Ultimate Durability synthetics are two of them—fully comply with each of these standards.
GF-5 is the designation used by the International Lubricant Standardization and Approval Committee (ILSAC), while SN is the latest in a long list of comparably-named designations from the American Petroleum Institute (API). According to the API, all oils with the SN designation also meet GF-5 standards.
These newer oils can be used in older vehicles, though they're likely to be a bit more expensive at first.
Look to still see plenty of SM oils on the shelf for a while, too. One sign of an SN oil is that most will likely carry a "resource conserving" stamp in packaging.
Here are the API designations you're likely to find in shops, as well as a few you might find in a dusty corner:
SM – Up until this month, the latest standard; better oxidation and deposit resistance; wear protection; and low-temp performance than the oils it replaced
SL – For 2004 and older automotive engines
SJ – For 2001 and older automotive engines
SH, SG, and SF – Each of these is considered obsolete