most put the cheapest crap, they can buy cough cough 19.95 oil change..
Well, next time around I'm going to run Walmart's Super Tech synthetic in my truck and then send off a sample to Blackstone. In the 1990s I ran a Jiffy Lube and we used Pennzoil oil which meets GMs 6094M standards. Saw no ill affects of using their Performax synthetic in my Buick either. Are there any oils in the USA that are not ethanol friendly?
Funny thing to me, when I read stuff like this, they all talk about water in the oil, stuff we NEVER even considered back in the day. All we were concerned with was getting our temps down as low as possible for maximum horsepower.
Someday I'll put a lower thermostat in the truck; either a 174 or 180. Stock is 187. We used to run 160s and my Buick even in summer, if I wasn't getting on it, would run 154 all day long.