Originally Posted By: Gary Allan
Quote:
I didn't say they were. Just that they're obviously not all the same because each manufacturer chooses to leave something out, or to use less of it. Its not nitpicking. Its a simple refutation to the supposition that none of the manufacturers left anything out, therefore no justification to put anything in.
(I hope I'm not "butting in")
I wouldn't say that (and this , again, is not an indictment of what you're doing). Different blenders use different additives to accomplish the same thing. It's not that they "left out" anything, they chose to use something else. It may be cheaper. It may work better with the rest of the package they pulled out of their behinds
I think beyond meeting a given spec, though, whether or not the goal is to achieve the same thing, the end result is not quite the same. Maybe very similar. Similar enough that not only are there no detrimental effects, but most won't even notice any differences (or that there are differences, or even what an additive package is). That is a reference to the average guy on the street, though, not the average poster here.
I'll fall back here on a simple point I've made before: too many variables in the oil's application. Engines are different, and often very different. As are driving styles and climates. Picking the right viscosity offsets the last variable, but with the others, I think certain oils do a specific task (as in run in a particular engine, or for a particular OCI) better than others.
Simple example: both Supertech dino and Mobil 1 EP are API SM & Energy Conserving oils. But if you were picking one to do a 15,000 mile OCI on, which one would you pick. I think that's an easy answer.
Likewise, if I owned a car with 300,000 miles on it and some leaks that were simply due to age, would I pick GTX, or MaxLife. My choice would be MaxLife, even though they are both API SM.
And I could do this all day, but that should make the point clear that there are enough differences to make the point non-trivial.
-Spyder