Originally Posted By: Gary Allan
Quote:
If ARX dissolves deposits then it does have solvent ability.
Well, no. MMO is a solvent. As I understand it, ARX, with its ester content, has an insatiable polar attraction to metal. I'm somewhat ignorant of the chemical mechanics ..but it surely appears to "displace" the deposits off of the metal and appears to have a chelating-like action to it. You don't see much difference in an ARX UOA to nearly the proportion of what has been removed from the engine. Surely a blip or two but most UOAs look not too far out there. If you use a Dyson analysis you can see changes in combustion efficiency and other indicators ..but elemental wear is not too effected in my observations.
Although I would not do it myself because I don't like introducing solvents into the engine, I'd say that IF you used MMO from near new that you may keep a clean engine ..but there's no two ways about it, you've altered the chemistry of the oil. OTOH, we've seen plenty of UOA to show that Auto-Rx doesn't alter visc or flash point ..or anything else .. and it won't breach some sludge layer in an aggressive manner exposing the sequestered mass to being bathed in the engine oil undermining the sludge structure (for those engines that have massive deposits).
Essentially, you can't use MMO without side effects to the oil. Whether that makes a difference in your usage is up for grabs. We've got some very fine oils out there with balanced add packs and whatnot and I'd rather not tamper with those properties if I can avoid it. I've already got to manage fuel dilution and air filtration as variables and I'd rather not add another introduced agent into the mix.
In a "flush" manner, I've tried MMO in the past and it was ineffective at fixing my annoying lingering start up lifter tick. This had plagued me for years. It was odd in that there was no immediate start up noise ..nor any when the oil was warm ..but shortly after start up, the valve train would cycle from ticking to silent .. back to clicking again until the oil got warm. This was indifferent to what visc oil you had in it. Synth or dino.. it didn't matter. I then said "what the heck ..let's see what this stuff does". It worked where all others had failed.
Now I've used MMO in fuel. I'm uncertain of its UCL properties ..but I do know that it does no harm as far as deposits or catalysts ..even in MASSIVE doses. It showed nothing but favorable (apparent - better starting, etc.) results in that usage. Terry seems to shy away from products that contain the main constituents of MMO ..but I haven't gotten the "fat" on why (not that I bothered to ask). He does, however, support the need for some perpetual add to fuel to add lubricity where there is none in todays fuels. He appears to prefer other products that have (perhaps) other benefits in terms of injector cleaning or whatnot.
I agree with you Gary in some aspects. The only question I have it this. How could something be around for 84 years and hundreds if not thousands of "old school" engine builders and mechanics still use MMO to date, if it may harm the engine because it changes the oils chemistry? When I built drag engines for the strip, about 1 in every 5 race teams I worked with uesed it in their oil at 1/2 pint to about a 5-7 quart sump. I'm not saying it doesn't change the oil's chemistry, all I'm saying is for something to be a "snake oil" so to speak and be around for as long as MMO has been, it must be doing something right.
