Alternating Exxon Elite and Aeroshell M/grade

[peter-h]

I have been doing this the last few 50hr checks, to see if there is any difference in the oil analysis.

The results have not really been conclusive, though the engine is making about 20% more metal with Elite.

However, I have seen a flyer from Exxon which says this is to be expected because their oil brings metal out of some sludge which was left there by "other oils"

So maybe a better test would be to run each oil type over two 50hr periods.

Or is Exxon's claim nonsense?

In any case, the two oils seems to be so similar that any difference is below the "noise" caused by factors like different flying patterns at different times of the year.

 

[Dr. O]

Differences in additive packages can/will cause changes in oil analysis... If you flip flop back and forth you will never know what is going on - the man with two watches is never sure of the time!
I do not bother throwing money away on oil analysis...
I do my own oil changes so that my eyes and my nose is in there... I cut the filters open and look for metal... If I can't see anything suspicious with my eye and with my magnet, and the engine is acting/sounding normal, then I'm good to go for another 50 hours...

denny-o

 

[Clark1961]

The word I've always heard from mechanics is to pick an oil and stick with it. The thought is that different oils react differently with seals so changing the oil brand will result in seal degradation and oil leaks.

OWT? I don't know. I do know that the additive packages do vary by brand and sometimes within brand (Aeroshell).

 

[peter-h]

Differences in additive packages can/will cause changes in oil analysis

Sure - different oils will cause different amounts of metal to get left behind