Originally Posted By: aa1986
I do agree that there is little reason to add additives to modern oil in sound running vehicles. I certainly would prefer that engines are factory clean (which mine appear to be through regular oil changes), but so long as the engine is running ok, in friend's and relative's engines, I have not been tempted to use additives and indeed even declined a complimentary engine flush on a friend's vehicle that had light sludge. I'd rather the oil take care of the "problem" slowly and I usually end up recommending oil with more detergents / more frequent oil change intervals.
While in some cases of additive use no doubt a sound diagnosis of an underlying issue was performed, I suspect that is the exception rather than the rule. Most decisions to use an additive appear to be made for emotional reasons or gut instinct rather than sound mechanical reasons. I certainly don't understand those who will add additive X without fail because that's what they were taught a long time ago or that's what they've always done.
I lean towards oil additives being snake oil with a few exceptions. That's a whole other thread though.
When I acquire a new to me vehicle or I start maintenance on another vehicle I like mmo as a crankcase cleaner.
I want to start off with a clean slate. If no deposits are visible with my Milwaukee inspection device,or its minor varnish with no agglometed chunks then I leave well enough alone and start a routine.
If there is visible deposits,like my friends traverse,then rather than a bunch of short intervals I'd rather nip it in the bud with 1 or at the most 2 cleaning cycles.
The traverse seems to be one of the problem variety where the oil life monitor was what you might call optimistic.
It belongs to my friends wife. She got the great Canadian oil change's special whenever the light went off. So always conventional and too many miles.
When I started maintaining it there was enough accumulated mud on the top end I couldn't see valve actuation,though I could certainly hear it.
So I went a grade thicker and a litre of mmo and a 3000mile/5000km interval and used my trusty motomaster(rebadged tough guards)oil filter.
The next interval I inspected the top end through the fill hole and was happy to see cams. Even my buddy was in awe because he saw what we started with.
I used M1 5w-30 for the next interval and have used either m1 or PP since.
I also told them to either get the ecu updated or run a 5000 mile interval tops. Now the insides are spotless.
I've got an inverse oiler hooked up to a vacuum line on my charger. Believe it or not I can tell by how it performs whether or not the can is empty.
At full throttle I can't feel anything different however with light toe in throttle inputs the engine is more responsive. I've even had my girl close and open the valve and not tell me whether it open or closed and I get it right every time.
So that cans the whole placebo effect idea.
Especially on a cold engine. It's very noticeable then.
I'm not saying it makes more power but it certainly increases responsiveness.
So I do believe mmo has its uses. In older lawn mowers and trimmers I find adding it sparingly to fuel helps the engines run smoother.
I use a tc-w3 in every drop of fuel burned in every gasoline,and Diesel engine I own. I have proven time and time again that our generators run longer per tank of fuel and based on the astronomical hours I get from the air compressors I think it's use as an upper cylinder lube has contributed to their long lives.
I've never had a carb or fuel injection issue with its use. On the contrary. Everywhere fuel touches is clean,I've never had to adjust anything on the carbs,even when ambient temps fluctuate significantly.
Used as directed it can't hurt,and just what if an upper cylinder lubricant does exactly what it advertises. For the pennies it costs why not use it.
I've never fouled plugs using mmo,even when grossly overdosed,though the exhaust was smoky and the engine was a bit sluggish.
Everyone has an opinion. Personally I don't close my mind to something til I see for myself one way or another.
I also like money,and not spending it for no gain.
So yeah I may buy something like an oil or fuel additive once. If it doesn't show some kind of tangible positive result I will not buy it twice.
A product has to save me money for me to use it. Whether it's less maintenance,which is why I use synthetic oil,longer intervals means less per mile driven.
If a product doesn't work as advertised I don't buy it again.
It's just that simple.