Marshall Booth wrote: > There have been rumors that Mobil 1 has be switched to group III oils > every year for almost 20 years. I expect that most of those rumors were > started by people that made their living selling group III synthetics. > It hasn't happened as of the last time I checked (about 4 months ago). > All if the Mobil 1 Extended formulas are mixtures of group IV/V oils.
After digging a bit and tracing links back through a couple of different forums, I found this, which seems to be the origin of the rumor: http://theoildrop.server101.com/forums/showflat.php?Cat=0&Number=749606&page=2&fpart=1&vc=1 "Just shot some M1 EP 15W-50 into the Gas Chromatograph and was surprised to find it based mostly on mineral oil (presumably Group III) plus a good slug of AN. It may also contain a small amount of PAO, but so small that I can't be certain."
