The WalMart here sells 2 brands. Injex and some other stuff in a blue bottle. $16 a gallon versus $30 a gallon. I have used over 20 gallons of injex in past sleds and never had an issue.
I have used everything and never had a problem with oil issues. I am running the BRP stuff now cause I got it at a good price. I have BlueMarble and Amsoil in my garage and I am using that in my dirtbike.
I have also used Redline and Klotz with no issues either, they smell good while being used but Injex is way cheaper and it works. Less money on oil means you can use more money on trips and other mods.
Mine was a black bottle, I thought it was like a marine/snow 2 stroke mix, not sure have to go get a car out of storage tonight and will check the brand. Wasn't either of the two you said, at least I don't think so...
I did this test. I'm not a big fan of seeing what it does under heat, as oil is all tested to perform under heat, thats what most of the research and formula is designed to work at. Take you oil outside and leave it outside on a cold night, or at least in the coldest temps you are going to ride in. leave set for a day or so. Now crack one of those open and poor it out into a cup. Does your synthetic look like tar? My cheap walmart oil doesn't, and thats why I use it. That oil needs to feed through pretty small lines when it is freezing out, and thats the biggest concern I have with the oil I buy.
As for the synthetic VS non in regular car engines, I see your point you were trying to get at, and if you want to talk similarities then, only one I will say is that I want my oil to break down and do its job.
I will not buy a synthetic that s designed to go over 6k miles before an oil change. I would rather change my oil every 2-3k miles and see that it is black but not burnt, I know it did it's job and was getting "used" where it needed to be. I hate using full synthetics just to drain it looking like the day I put it in there, what was it doing in there over all that time? But thats just my opinion, it's what I have done to all the vehicles in my family (current): 1918 Model TT, 1926 Model T, 1946 Ford Tudor, 1953 Chevy 210, 1995 Ranger, 2001 F350, 2002 Gram Am, 2002 Ford Explorer Sport Trac, and will continue to as I have never had engine problems with any of my vehicles.
I agree, I dont think it is so much the brand that you use, if you buy into the expensive oils or not, but whether it gets enough oil.