Since the beginning of BITOG there have been many members who have tried to shoot MMO down for various reasons, but nobody has been successful at squashing this product. When I 1st came to this board I called MMO Old School, but when I tried it I realized the product worked.
I 1st started using it in the fuel and I noticed my carburetor ran alot better, I then started using it in my oil when a member here did not see results with auto-rx. I cannot say that auto-rx did not work for me since I did go through 22 oil filters in 24,000 miles, so it was releasing junk to my oil filter, the only time I noticed a difference with auto-rx was when I changed an oil filter that was saturated. With MMO I noticed it was in my engine as soon as I drove out of the driveway, I also did not have anymore oil filter problems, my thoughts are that MMO dissolved the contaniments better than auto-rx and therefor I was not clogging up my oil filters. I never really noticed a change in color of my oil with auto-rx, but I did with MMO.
Auto-Rx did not clean up my valvetrain, there really was not much to clean, I could scrape the cylinder head with a screwdriver and get some residue, after having MMO in my oil for 7000 miles my valvetrain is totaly cleaned up and I cannot scrape anything off with a screwdriver, I can even read the serial numbers inside the cylinder heads.
There are too many positive testimonials with using MMO in the engine from members that we really cannot say that the product does not work. I notice that my engine starts right up from having MMO in my fuel and oil, I have better throttle response and I am getting better gas mileage. I believe this product is keeping my engine clean, and therefor my oil can easily travel to the top of the engine and back down to the oil pan with no restrictions. I also noticed that on my 1st and 2nd OCI's with MMO that my oil got very dark, and on this 3rd OCI the oil is staying clean.
I also notice that with MMO in my fuel, that my carburetor is staying clean and when I have pulled the spark plugs to check them, they are also free of deposits.
If you are getting great results with auto-rx, then stick with it if that is what works for you, I just found MMO to work better and I always use the product that works best for me.
A Clean Engine is a Healthy Engine, so just pick the oil additive that is going to keep your engine clean, and some members may even find that oil's like Pennzoil Platinum and Pennzoil Ultra do a good job cleaning an engine and also do a good job keeping an engine clean.
I used Mobil 1 from 50,000 miles up to 200,000 miles and I then used Amsoil between 200,000 miles up to 343,000 miles and my engine was still dirty, looking back, since my valvetrain was not that dirty I think I just may have had some junk in my lifters, maybe the new oil's like PP and PU are better at keeping an engine clean, but from my past experience I am not taking any chances, so I will continue to use MMO in my oil.