Originally Posted by Hydrocruiser

[B]Who There is one "downside" to heavy parafinic based oils and that is they generally have a tendency to sludge up an engine if pushed beyond their limits. The parafin which is a wax can proceed toward it's natural tendency as it breaks down to form carbon and in combination with a waxy matrix you get sludge and later even still "coking".

I would imagine there are stabilizers to help reduce this from happening but none the less these types of oils have been reported to on occasion lead to sticky valves etc. if not changed frequently enough to a greter extent compared to parafin free products.



Here are the specs it is made to:

http://www.mercurymarine.com/uploads...1/003-1647.pdf

Originally Posted by minxguy

The specs are an Material Saftey Data Sheet tells you nothing of the elemental composition of the oil.

Sludge....a black emulsion of water, other combustion by products, and formed primarily during low temp engine operation. Sludge is typically soft, but can be very hard. It plugs oil lines and screens, and accelerates wear of engine parts. Sludge deposits can be controlled with a dispersant additive that keeps the sludge constituents finely suspended in the oil.

Ken

Originally Posted by minxguy

Hydro, don't ever discount a petroleum (parafinic basestock, not napthenic basestock). A quality built lube with a parafinic base stock and the right additive package will perform excellent for 98% of the readers of this thread. Group III bases are what we are talking about, highly refined petroleum base stocks.
Oh and thanks.Ken

Originally Posted by shark42

German Made Castrol is still 100% PAO as well

Where do you get german made castrol? My BMW calls for synthetic and the oil cap says Castrol is preferred. Thanks