[Sirrotica]

Every time a oil (or a filter) thread comes up 99.9% of the replies miss the root cause of engine wear. It's not so much what oil is in the pan, as much as how clean it is kept during the time it's in the engine. If a full flow filter actually kept the oil clean you wouldn't have to drain it frequently to get all the contaminants out of the engine that the filter can't physically remove.

From the time the engine is started for the first time with fresh oil in it it's being constantly contaminated by combustion by products as well as the contaminants (mostly silica) that are drawn in through the induction system that an air filter is physically incapable of removing. It's a fact that no amount of engineering or aftermarket do dads can prevent. Some of the intake contaminants make it into the oil and because the full flow filter pores are usually 40-60 microns they continue to re-circulate abrading all the moving parts that are oiled by the pressurized oiling system.

The size particulate that causes the majority of engine wear is 5-10 microns, well below the pore size of any spin on filter. It's documented if you want to do a search.

By pass filters remove roughly 98% of the sub 40-60 micron size particulate in the first pass. Most by pass filters remove particulate down to 1-2 microns reducing engine wear in the neighborhood of 63%.

I.E. If you get 200,000 miles before the engine needs a freshen up, or a rebuild with a standard filter, with a by pass filter you'd be in the neighborhood of 600,000 miles.

Ring seal is likely the best indicator of engine wear so your going to have more compression for a much longer period of time. Even if you don't run the engine until it's got extensive blowby, you're going to have better mechanical seal keeping the contaminants out of the oil and better compression longer. Not to mention that you can keep the oil in the crankcase many times longer than you can with a factory designed filter system, and it will be just as clean when you do drain it as when you poured it in. It doesn't keep getting more abrasives in it the longer you run it.

That expensive oil ($8-25 a quart) that has all the properties in it that you scoured the web to find out how good it is, isn't going to be shot due to contamination in a year, or 3000 miles. Oil that is kept properly filtered also does not eat up the additives like dirty oil does, making everything associated with the oil last many times longer.

FWIW, even if your engine is currently operating without a real oil filtering system, the addition of a by pass system will start benefiting the engine as soon as it's installed. Removing sludge and actually removing all the contaminants from the engine and the oil.

I don't care what oil you buy, at what price, it won't have as a dramatic effect of reducing internal engine wear by 63% that a by pass filter system will.