DETERGENT in motor oil

[BSNMOE]

Is the sole purpose of detergent in motor oil longer drain intervals? I realize that detergents keep the engine clean, but how dirty can a hot running engine get in a few thousand miles. Would we be better off using racing oils and changing oil every 3000 miles or, if your a little lazy, mixing racing with regular oil and change it at 5000 miles? When I hear "DETERGENT", I think of a caustic solution washing down my cylinder walls and bearings. Some oils, like AMSOIL, have crazy long drain intervals because of a high detergent content.

[Joe Bob]

"Detergent" = marketing......

[db_cooper]

I remember some early VW air cooled engines where the spec for the engine oil was 30w Non-Detergent. Back in the day several engine oils were available in that spec and those old bug engines ran fine, until.........

The problem was, when the owner or mechanic changed back to a regular engine oil with detergents, the gunk which had settled into the bottom of the crankcase got pulled back into the oil pump and bearings. Bad news for the engine.

Those old engines did not have a proper engine oil filter, only a screen in the crankcase. The mud in the oil was a real problem.

I would suggest using an oil with a complete additive package, including detergents. With a modern oil filter, you want to allow the oil to keep the engine as clean as possible. The chemical technologies are very safe for your engine. Do not be concerned. Our 911 engines were factory fill with high detergent oils, like Rotella T.

There are some very good high performance oils with a detergent package, Brad Penn Swepco, etc.

[ClickClickBoom]

I use about 6 oz of Tide liquid concentrate after each oil change, side benefit is my oil smells fresh and outdoorsey!
eric

[Wayne 962]

Don't confuse "detergent" with anti-friction wear components which really do work well. I would not go beyond 5,000 miles with an oil change for *any* car - the longer oil change intervals were started by the eco-friendly people to cut down on the amount of used oil. In particular, on older cars, gasoline mixes with and contaminates the oil - it needs to be changed often.

-Wayne

[Bill Verburg]

Back in the days I raced 2 strokes they needed non detergent oil. AFAIK all 4 strokes since the '60s at least have used detergent oil. I do vaguely recall that in the '60s even into the '70s Porsche spec'd straight 30 weight oil. The controversy at that time was straight 30 vs the new fangled 20w50

[Por_sha911]

Eric: you should really put that in green letters so that if a newb comes along and reads your post...