http://www.pceo.com/images/GF6A-vs-GF6B.jpg
Looks like just a fuel economy increase. On another page, it mentioned the Honda 0W16 oil meeting the GF6B spec draft based on current tests. These two factors lead me to believe its for Ultra low viscosity oils only. I can't find anything for certain, though. The spec draft is 404'd.
So GF-6A is the GF-5 replacement while GF-6B is a new category.
GF-6A will be backwards compatible with GF-5, GF-4, etc. It will contain grades SAE 0W-20, SAE 0W-30, SAE 5W-20, SAE 5W-30 and SAE 10W-30.
GF-6B will be new SAE 0W and 5W oils that will not be backwards compatible. A.K.A. You will not be able to run it in older engines. This new 6B specification will also carry a new SAE 16 oil weight.
Thanks, the video presently on http://www.pceo.com/market-consumers
also talks about this. As talked about in the video, having both A and B may confuse people.
Originally Posted By: MikeySoft
As talked about in the video, having both A and B may confuse people.
Further API classification will hopefully allow for better clarification - such as how GF-4 is SM and GF-5 is SN.
