interestingly, google says gf6 is approved for modern engines, where gf5 was not. i wonder if this has been part of toyotas problem
For the technical definition, see the eighteenth edition of the API 1509 standard (PDF), section Q.6, pages 130–138; see my previous posting for background on the American Petroleum Institute’s role. Several suppliers and marketers of engine oil and additives, including Lubrizol, Mobil, Phillips 66, and Pennzoil, have pages explaining some of the reasons for developing a new specification. Even the latest (MY 2020) Prius cars were designed to use engine oil meeting the earlier ILSAC GF-5 or API Service SN/RC performance standards, so they will also be able to use oil meeting the ILSAC GF-6A or GF-6B standard, of suitable viscosity grades, once it is available next year.
Thanks Electro! Oil company mumbo jumbo; as long as my Prius keeps running well, I think I'll be OK. Remember when we were youngsters, and Shell Oil Company told us about their grand gasoline additive TCP? And we all went out and filled up with Shell with TCP? And then comedian/philosopher/petroleum scientist George Carlin told us that TCP stood for Tom Cat's Piss?
