Excellent responses everyone!
I was pretty active at BITOG trying to learn-n-share quite a few years ago when ARX was a daily topic and we were all sharing pictures and such of our progress with it. I always sort of liked the story and concept behind it, and figure that in the right applications used as instructed it might be a useful tool. Like any "test" of an additive performed by an individual, without a duplicate control group there's really no way to say for certain whether it did anything useful. That said, with almost no talk of it here when I checked back in recently, I was thinking that maybe the communities view of the product had changed drastically in the last few years. I guess it's just taken a back seat for discussion here.
My results with the product years ago were mixed. I think it played a part in reducing oil consumption on my isuzu 3.2L SOHC (which is still running that original engine today, 240K miles), and I believe it may have also done something useful in the manual transmission in terms of cleaning, as the rebuilder commented on an unusual cleanliness inside the tranny when he was working on it. (it wasn't broken, was having it gone through since it was already out for a low-range gear swap in a married T-case).
In my sludged up suzuki I didn't really see much useful cleaning from it, even after many cycles.
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Reason I bring this thread up, is that I was thinking about picking up a few bottles of ARX to help get a new-to-us used car into a nice clean baseline state when it rolls over the 100K mark.
We just bought an XC70 with 94K miles on it. It has a low pressure turbo engine that has had its oil changed by the dealer every 7500 miles since new (likely castrol dino).
The transmission, an AW55-51SN is one of these transmissions that in most applications calls for fluid changes, but for some reason, Volvo decided to call it a "lifetime factory fill" sort of deal, likely to reduce cost of ownership numbers.
My feeling is that with that sort of engine OCI, and (likely) 94K on the original 10 year old transmission fluid (brownish red but not burnt), both are in acceptable condition but might benefit from some additive based cleaning before moving forward. I'm thinking I'd like to do a drain-n-fill (which will get a little less than half of the fluid, requiring only ~3qts) on the tranny, add some ARX (recommended 6oz I suppose), and run it till 100,000 miles, then do a complete flush at that time, giving me a nice round baseline starting point on transmission fluid, and hopefully some valve body cleaning, which is the main source of trouble on these transmissions. I was also thinking I'd do an ARX cycle on the engine with a couple ~2500 mile cycles (1Xclean/1Xrinse) with a decent quality dino, lining things up nicely to get the thing back on long OCI's again starting at 100K, but with a synthetic oil this time around.
Am I just making myself feel good with all that, or do yall think it's a worthwhile effort?