Originally Posted by Dyusik
Everyone does. You can't get all the old oil out. Especially on a thing like RX Mazda, where an oil change is more like a ATF drain and fill. My FB UOA looked better than a straight fill, And that stuff was Frankened out good.
Exactly
Lots of guys do it, we hear of guys all the time running a filter two and three oil changes and use a different oil each time