Posted by Don in Missouri on Sunday, November 14, 2004 at 8:51PM :
In Reply to: Oil type? posted by Dan on Saturday, November 13, 2004 at 1:50PM :
The only non-detergent oil I usually find is straight 30 weight, and I have to ask for it. My local store keeps it behind the counter. They don't put it on the shelves out front.
Detergent oil keeps the dirt suspended in the oil. This is OK as long as you have a full-flow oil filter. If you don't have all your oil going through a filter, then the detergent is carrying the dirt right through your bearings.
Non-detergent oil lets the dirt settle out. it makes a mess on the inside of the engine, but that dirt is better off on the walls of the crankcase than being recycled past the bearings again and again.