I'd like to restate that MMO was VERY useful in fuel years ago. Gas had lead in it, and MMO combated it on the valves, CCs, and spark plugs. That is why many small aircraft and vintage owners use it today [leaded fuel is still around for them].
Many cars got internally dirty, and MMO helped free countless lifters, and clean up things. Old time rebuilders would run MMO in the crankcase before tearing things down, as well.
So what about today?
MMO combats the diminished lubricity of alcohol fuels. Better for the fuel pump, primarily. It certainly has helped with sticky and balky fuel level sending units. Cleaning? How can we measure this? I can say it does not add to the problem.
In the oil? Only for special cases and special needs, IMO.
Many cars got internally dirty, and MMO helped free countless lifters, and clean up things. Old time rebuilders would run MMO in the crankcase before tearing things down, as well.
So what about today?
MMO combats the diminished lubricity of alcohol fuels. Better for the fuel pump, primarily. It certainly has helped with sticky and balky fuel level sending units. Cleaning? How can we measure this? I can say it does not add to the problem.
In the oil? Only for special cases and special needs, IMO.