Quote:
Originally Posted by bluesubie
Why? Because it has more Anti-Wear additives, resists fuel dilution, and stays in grade? Also, Amsoil 0W-30 is not a European oil if that's what you were referring to. It would probably be a better oil if it were.
-Dennis
As a previous engineering major, I would be hesitant in using anything that was designed and then advertised specifically for a group of different automakers.
With more research in a specific oil, maybe I'd be more at ease, but with all the other good oils out there, like Rotella, I would have no good reason to switch off to an oil advertised for European cars.
Also, while the characteristics you mentioned are generally referred to as "Good" in engine oils, it's hard to jump conclusions that all oils labeled "European" would always be better than if it wasn't European, since we own Japanese cars.
As far as I am concerned, Japanese automakers tend to make their engines "tighter" and european automakers tend to make their engines "looser" ... which is why many european cars you see use a thicker oil than japanese cars. This is not always the case because we've seen GC work well in a Subaru motor, but just something to consider. But from what I've seen/read on here, GC is only close to a 40 oil, it isn't a true 40 weight oil. (Not sure if this is true, straight from nasioc
)
Also I want to address one thing about those who say that 30 weight oils are bad because they shear to 20 weight. The people at Subaru who decided that the recommended oil should be 5w30 are the engineers.. the same people who designed/tested the motor and oils. They are engineers, they are not dumb. If they say that 5w30 is recommended, they already considered the fact that there is a possibility that the oil can and will shear down a bit.
and no, I wasn't referring to the Amsoil 0w30.
I'm not making any claims, there's just too many flawed logic in here and I'm just trying to maintain some integrity in this thread.
EDIT: I realize you said that European oils stay in grade. Being that the recommended oil change interval for Subaru is 7500 miles.. and even longer for some European automakers, do you have any data to back up that claim? I'm not calling you out, I'd just be surprised and pretty impressed if a 40 weight oil can stay a 40 weight oil after 7500-10,000 miles.