If you really want results I say that Auto-RX cannot be beat. It worked for me and several other guys at this web site have stated that it worked for them.
Marvel Mystery Oil has been around forever. It is used in small remote controlled aircraft. It was used in bombers in World War II. It may work but I never saw any real results from it.
Beats me if LC works or not. The smell of LC and FP is overpowering to me.
FP, Neutra, Gummout Regaine, BG44K, and Chevron Techron are good fuel system cleaners as far as I have been able to determine. I say use BG44K a few hundred miles from an oil change if you really have plugged up fuel injectors. I have noticed that BG44K seems to be available at Toyota, Honda, and Saturn dealerships. For maintaining a clean fuel system I have noticed some results using Neutra and Gummout Regaine.
There really are not a lot of other products that I believe in. I think Lubegard makes some good stuff, at least for automatic transmissions and power steering units. A long time ago when I tried their Engine Treatment and my car seemed to run better. They also make a pour in engine cleaner that one guy at this site says that he uses.
Schaeffer's #132 or Valvoline MaxLife oil supplements seem to have some usefulness. Especially now that SM oils may benefit from more additives.
Beyond these products right here I have ZERO confidence it anything else.
Re: auto-rx VS. seafoam VS. mmo........#283684 01/22/0511:20 PM01/22/0511:20 PM
Auto-Rx - yes, a class by itself. I don't know about those who use it prophylatically ..but for remedial use it's about the best thing since sliced bread.
LC- it's alleged to be an oil "side effect and degradation inhibitor". I haven't used it.
MMO - I've used it ..to excess.. and had good results in fuel additions. I've seen little in oil one way or the other in terms of "apparent effect". It may in fact do something ..but is kinda neutralized when a product like Auto-Rx is brought into the picture. IMHO it's on the good side of the $/snakeoil meter. It does wonders for my oil fired boiler in terms of a clean stack.
Seafoam works well as a fuel system cleaner. As a engine cleaner ...it can't compare to Auto-Rx. It can't hang around that long ..or so I imagine. I would think that it evaporates in a very few miles in heated oil.
I haven't used LC ..but it appears to be more of a product that enhances or reduces side effects on oil. It may result in a cleaner engine ..but isn't an engine cleaner per se`.
Re: auto-rx VS. seafoam VS. mmo........#283685 01/23/0503:02 AM01/23/0503:02 AM
I've never used Seafoam or LC so I can't comment on them. MMO works great for freeing up stuck tractor engines. However I'd never put it in my vehicle. AutoRX is fantastic if you follow the directions completely, and FP seems good too.