Nice numbers rh77. You know this forum has high standards when members use technical terms such as 'outlier' in casual conversation.
Thanks -- "Statistics" class comes back to haunt me once in a while
But...That's one of the many reasons why I've stayed here for so long -- it's the dedication to the Scientific Method that members respect. If someone has a claim, they'd better have some data to back it up -- if they can't find it, many run their own tests.
According to the "experts" (John Dozsa, 30+ years with GM, engine development engineer; can you get much better than this?) : <www.w.corvair.org/pipermail/virtualvairs/2005-july/028037.html>
...as long as you match viscosities (I'm loosely quoting, here) , there is no difference whatsoever in dino and synthetic oils! Loosely obey the mileage recommendations for changing...and don't worry about it! It's your money!
Synthetic oils splashed on the scene when Madison Ave. decided "Let's plant a worry-seed out there! We'll sell 'em a cure... for more money...help 'em think they're doing something better for their rides."(My quotes...I love being manipulated!)
I'm all finished with this ridiculous argument! I'll say no more...I have to go change the oil in my C5 'Vette...5 1/2 quarts of "El Cheapo" 10W40 oil ...plus a pint of GMs "Break-in Assembly Lubricant". This stuff is so slick! Zinc-based oil booster, altho' GM recently changed the name from EOS(Engine Oil Supplement) when they got wind of a coming FTC action...suits against ALL the oil-supplement people, for making "unsubstantiated claims". GM made no claims...but didn't want to pulled under by these (Slick 50, STP, Duralube, Z-Max, Prolong, and on and on ) "additive" brands. Hey! It works! How do I know? I don't! I listen to those who do! I read a lot! I listen.... I decide, then I relax.