Originally Posted By: finalyzd
So by changing my oil every 3000 miles is actually cause wear?
Sorta, kinda.
The point is that oil protects better when it's
slightly used than when it's totally fresh from the bottle.
Let's say it takes 1,000 miles for the oil to start working better. This number is a totally random guess but it serves to make the point. So, if you change your oil every 3,000 miles, your engine spends 1/3rd of its life with oil that is too new. However, if you change your oil every 6,000 miles, it only spends 1/6th of its life with oil that is too new.
Obviously you don't want to take this too far, because the oil will eventually break down and not protect as well. But you don't want your OCIs to be too short, either.
Originally Posted By: finalyzd
And a filter actually filters better threw age?
As they get clogged up, they let less and less through. However, this also restricts oil flow, which is why you always have to change them eventually.