As has been previously mentioned, the "results" from an application of Auto-Rx (or two) can be dramatic in those cases where a lot of 3rd party material is loosened and trapped in the filter. Obvious heavy deposits are going to impress visually, pictures of "before and after" where brown deposits on valve covers and valve train are removed show remarkable cleaning.
But as Terry has mentioned in previous threads, it isn't really about what you find in the filter but what the results are in cleaning the engine internally. I certainly expected to see more gunk & grit in the filter pleats on the 420SEL than what I saw since it had over 130K. However, good maintenance practices and good oil had maintained the engine in a cleaner state than what I had expected. I was encouraged, maybe even elated.
The grit that I did find was substantial and I don't doubt it was removed from areas that a conventional flush wouldn't have affected. Hopefully it was from around the rings.
The SVX wasn't very "dirty", either. I wasn't as surprized there as it had 3K changes all its life (that one we bought new), but there was still an amount of fine, gritty material in the filter folds. Job done. Haven't had it in the F250 long enough to even pull the filter (I'm really interested in seeing what's in THERE!) but it sure SEEMS to be running smoother already
When you are getting under 10 mpg hauling a ton+ camper, any increased mileage will be warmly appreciated. But that's not why I used it.
I guess what I really don't understand is the crack about it not being "cost effective"? What does it cost to remove even the valve covers from any of these three vehicles? In time (mine, fortunately, vs. the dealer or a shop @ $50-70 per hour) or in parts? How about pulling off a head, or dropping the engine (SVX) or pulling it (as in the MB or the F250)?
How can a $50 investment not be cost effective if it loosens up just one ring set? Or one seal leak? Or one noisy lifter? Or even if it just cleans up the valve train enough to make the correct mechanical diagnosis just that much easier? What about the prospect of reduced wear? Emissions test problems, anyone? I don't see that there is actually an alternative effective treatment for this type internal cleaning other than Neutra. And some feel they actually compliment each other.
I guess the fact that "your results may vary" may be lost to some... Either that, or their expectations are too high or are, perhaps, simply unreasonable to begin with?
Then there is the guarantee...
p.s. I'm sure glad I don't have to try and make everyone happy
