Originally Posted By: elwaylite
I would concur that the Lucas made my 2.4 toyo less harsh, but the cleaning addition of the MMO has me intruiged.
I already run a Techron shot at each oil change, so I may only need a UCL. I've tried to read up on it, but it appears the only thing a UCL really does is smooth out an engine. This is not a bad thing, but I dont see it as a longevity issue.
Real world, I think changing your oil regularly with the good stuff and a Techron treatment is prob all you really need to do.
The UCL will make the engine feel smoother, and keep the plugs in good shape as long as you stay at or below the suggested dose. You can OD with MMO and not foul the plugs, but why tempt fate? You can definitely foul plugs with TC-W3, quite easily in fact.
As far as longevity goes a UCL like MMO or TC-W3 coats the cyl walls with a thin film of oil. It is IMO that the thin film of oil reduces ring and cyl wear, makes a better seal, and might increase compression slightly, which would explain the better smoother running engine. However I've never had to tear an engine down for a rebuilt so I never mic'd up one of my engines,. I have nothing to go by, for the people looking for cold hard facts. I've rebuilt engines that were shot, history unknown.
Where a top oil also shines is in cars that sit for long periods of time w/o being used. The top oil will prevent flash rusting, and protect the cylinders and rings from dry starts., reducing wear. Those examples plus the fuel savings make it worth the expense, to me.
As a side note, my plugs stay nice and clean, and the porcelin has a slight pink hue to it when I pull the plugs.