"Billgran" wrote in message
...

"John H." wrote in message


Bill, I just bought a new Key West with a Yamaha 150 hp 4 stroke. In
your
opinion, should I even consider using an oil other than the Yamaha oil
recommended for the engine?



If you want to use a different oil, choose another outboard
manufacturer's oil as your first choice. OB companies formulate their
lubricants for better carbon cleaning and longer engine life.
Aftermarket TC-W3 oils are enough to keep your warranty in force, but
remember that they are made for a price point, and may just meet the
TC-W3 requirements. One test allows for 14% scuffing of the piston
diameter to pass, so an oil that only scuffs 12% of the piston can say
theirs EXCEEDS the TC-W3 specs. the OEM oils do not allow any scuffing
in that test. Think about it, if all the oils were the same price per
gallon, would you use the manufacture's designed oil or an
off-the-shelf brand?

I'm not saying other oils are bad, but they may not perform as well as
an OEM one, especially in the carbon cleaning department. Oil opinions
have always been a can of worms, just like discussions on religion and
politics.

Bill Grannis
service manager

Does the TC-W3 spec also apply to 4 strokes, as the original question was
about 4 strokes.?