Whatever the dealer's reasoning, 5W-30 is the recommended oil and that's what ought to be used, at least for the time being. I'm not opposed to trying non-spec weights, in fact I'm getting ready to try out 5W-20 in my 5W-30 spec'd Civic. But that's only after getting some solid baseline data on how 5W-30 performs.
If the engine is still breaking in, which we do not in fact know, then of course this latest UOA shows improvement over the previous. This is obvious and not really useful for the purpose of comparing wear #s. That's part of why I see little value in very early UOAs.
I did a search and found another Mazda 2.3 that showed 11 ppm of Cu at 10k. As you said, it was a normal, non-turbo, non-DI engine, and perhaps not a valid comparison. But, I don't know where the Cu in this engine actually is. Is it anywhere that either the turbo or the effect of DI would show? Do you know the metalliurgy of the various components in this engine?
As you said, wear is dropping compared to the previous sample. My point is that if this engine is still wearing in, this is the only expected result. ANY oil would show the same. If this engine is finished wearing in, then this Cu value may be problematic. WE DON'T KNOW when these engines stop showing elevated break in metals. I'm just trying to go on what we've got. And right now we don't have much. I'm trying to point out some unknowns that merit some additional attention.
jeff
If the engine is still breaking in, which we do not in fact know, then of course this latest UOA shows improvement over the previous. This is obvious and not really useful for the purpose of comparing wear #s. That's part of why I see little value in very early UOAs.
I did a search and found another Mazda 2.3 that showed 11 ppm of Cu at 10k. As you said, it was a normal, non-turbo, non-DI engine, and perhaps not a valid comparison. But, I don't know where the Cu in this engine actually is. Is it anywhere that either the turbo or the effect of DI would show? Do you know the metalliurgy of the various components in this engine?
As you said, wear is dropping compared to the previous sample. My point is that if this engine is still wearing in, this is the only expected result. ANY oil would show the same. If this engine is finished wearing in, then this Cu value may be problematic. WE DON'T KNOW when these engines stop showing elevated break in metals. I'm just trying to go on what we've got. And right now we don't have much. I'm trying to point out some unknowns that merit some additional attention.
jeff
