Barbara Harris wrote:

> is it possible to substitute power steering fluid for a synthetic brand oil
> additive e.g., slick 50, prolong, duralube?

Read the vehicle's owner's manual. It tells you to not add anything to
the engine oil, usually for good reason.

Power steering fluid may be like Dexron transmission fluid (for some
cars Dexron is even specified as the power steering fluid), in which
case it contains a high enough concentration of detergent to damage the
engine in the long run.. This is why when a pint of Dexron is added to
the engine oil to clean out a stuck valve lifter, the oil and filter
have to be changed in 100 miles and then again in another 100 miles.

Consumer Reports found no reduction in engine wear in NYC taxicabs
running Slick 50, and, contrary to what additive sellers claim, regular
high-grade motor oil (anything with an API certification of SL or SM,
in the case of gasoline engines) contains all the needed additives, and
at least 20% it is additives. So if your engine uses $10 worth of oil
(5 quarts), that's $2 for the additives, compared to $10-20 for a
bottle of Slippery-50. (actually it may be more like $1 because
viscosity improvers are a different type of additive). Would you
rather use an additive package that's been tested and quality certified
by the API and approved by the company that designed, built, and
warrants your engine, or would you rather take your chances with
something uncertified and marketed with false claims?