How often do you change your oil? How much oil is "hardly burning any oil"? 39,000kms per year for 13 years is a good run, but I would give credit to your routine maintenance rather than to any additive you've used.

 

My Mazda 626 did 275,000+ miles (nearly 455,000 Km) before the general mechanical condition - clutch, pulleys, axles - killed it. The engine was still fine.

What was my secret? Change the dyno oil and filter about every 5000 miles. I drove it from 28,000 miles to about 175,000 miles driving in Ohio all seasons, daughter had it the last 100,000 running it in Austin TX.

Oil with proper oil pressure is what operates as a bearing in a plain bearing engine. Pretty simple - keep oil and pressure there and the two pieces remain separated. The oil will keep the parts separated. Oddly enough the pressure isn't really what does the job keeping it in. It is the constant rotating of the oil varying pressure around the bearing surface increasing the pressure needed to squeeze the oil out, which is far above oil pump pressure, but works. The clearances are tight enough the short time of pressure on compression and power strokes aren't enough to squeeze it out... liquid bearing!

Ball/roll bearings are another story, but still the bearing skates on a thin film of oil, rolling over it even under the pressure of compression and power strokes. Heck they survive with that small 50/1 oil mix in a two stroke - living in a 4 stroke should be like oil paradise to the engine!

So the bearing test for metal to metal contact really means nothing - unless you run out of oil or some other foolishness like jamming your cam drive or loosening the mount bolts to let it click over, then tightening it, both of which could cause tension on the chain to break the oil film in the bearing. Then maybe you need something like that.

I do believe synthetics can help to an extent in gear boxes and clutches, actually experienced it with the old Gold Wings. It would allow the clutch pack to break loose easier and made for smoother shifts. The oil weight comes into play too in some cases too.

Magic mystery lubes for engines don't really play well in my mind based on the fluid dynamics. Now using own for your mountain bike forks where no pressure is present... maybe it makes sense.

Oh, I also noticed that oil thing didn't compare regular oil in that bearing test. Wonder why?

 

I changed my oil every ~7000 KM (5000 miles) because I work in the woods and my company provides all the basic needs for my truck, including oil. (I used Mobil1 High Mileage 5w30) and always used Motorkoke to try our if it helped as it didn't bother me they usually paid me back for these kind of items. Also, by hardly burns any oil I meant every vehicle eventually starts burning oil when the engine starts to get used up, by the time she burned enough oil for me to need to add some i'm already on an oil change.

 

The way a couple of those thicker oil treatment additives built up and wrapped around the center during the bearing test was illustrative.. talk about a hp killer!

 

I think synthetic oil if a definite plus. I have used many slick 50 type additives over the years before you could get Syn oil readily available. I think that being said, this stuff is all hype, maybe it was worth it 20 years ago when we only had dino oil.
BTW can someone explain to me how an additive can soak into an engine block? A steel sponge? I don't think so and its a total BS statement, that alone would make me run away. There's no way it can soak into a cylinder wall, they are highly polished at the machine shop and the pores are too small to let it soak in.

 

I think it's all in your head man lol like stated before these additive companies claim all kinds of things so you buy it! Just like Lucas Oil Stabilizer says you can use it 50%-100% in your manual tranny and differentials. Have you seen how thick that stuff is? No way I'm Puttin that in my rig. Modern synthetic oils have everything in them now so you don't need any additives.

 

Lots of good comments here. The concept of an additive filling in rough spots is a good sales method...because the lubrication in a decent additive does just that...but...so does a quality motor oil. Smooth surfaces or rough, quality motor oils keep the metal-to-metal contact to an absolute minimum under the worst conditions. It's what a good motor oil is supposed to do. The hard part about qualifying additives is that it is nearly impossible to compare them to how the test would have turned out with a top drawer motor oil. Today's quality motor oils have impressive additive packages in them already.

Sythetic motor oils, for the most part, actually contain a good bit of petroleum product. It's just that a lot of chemical and additive manipulation occurs to produce very strong and consistent lubrication molecules. It's just not necessary to introduce aftermarket additives to many of these top drawer oils, but most of the quality additives don't actually hurt anything...except in those cases where the particular additive might alter the viscosity in engines that have a sensitive design to a very specific viscosity range like I mentioned before.

 

Good comments. To an extent all materials are porous at a molecular level. It just depends on what is trying to permeate the surface. Even plastic gas tanks have some of the additives in gasoline seep through the plastic - causes the stickers to lift. So at a molecular level oil and other lubricants like that do soak in surfaces.

As said, it is trying to prove the product actually does anything. Same with oils. The only real proof about best change intervals can only be done by destructive testing. Run the oil doing samples, until the engine breaks down due to oil failure. Use the information to formulate the ideal interval. A long long process - and I'm betting the manufacturers and oil companies have done similar testing to make their oil change interval claims.

Everyone gets hepped up on changing oil every 2000 miles making claims about break down and such, but there's nothing proving it makes a difference - except oil company claims. There's always someone like me who ignores the oil for another 3000 miles (5000 total or more) with the same results.

The bearing test means nothing except if you have a failure in the system that lets the surfaces touch. A good oiling system will not allow that, the bearing is the oil film between surfaces. Thus the reason for two of us having similar mileage results, one with the additive and one with only dyno oil.

But there is nothing wrong with using additives if one feels they work better, as long as they don't cause damage.

 

Those 626 engines were great! My dad and I put over 200k on one before the tranny died. Cost more to fix than it was worth but the engine never used oil or smoked.

 

That was why it went away at 275K - the clutch was shot, the belt pulleys were worn out, axles bad. Just not worth fixing any longer. The engine was still starting and going strong.