> The EPA has forced the oil industry to take zinc
> out of oil,
That's a bit of an exaggeration. Rather they've reduced the amount of zinc
by 30% or so.
> and that will cause wear on cams.
Only if you don't change the oil often enough. Increased zinc levels don't
provide more protection, they just provide the same protection for a longer
time. And since most people change their oil far more often than is really
necessary, I doubt it will be a problem. If you really want to be sure,
start having your oil tested.
> The diesel oils still retain zinc in their oil.
Might be true, but I couldn't find a single source on the web that quoted
how much zinc was in their oil.
> They are recommending to use
> Shell Rotella T, or Castrol Tection that is type SJ or any oil
> that carries the type SJ specs, which contains zinc.
>
> Comments from old LBC owners?
I don't have the data to prove it, but I strongly suspect that any SM oil
will still meet SJ specifications. Thus the key information is not whether
it's rated SJ or SM, but how much zinc is present (assuming you think that
is important).
BTW, there is a test for "cam wear" in the API rating ... not specifically
camshafts I believe but rather an extreme pressure test in a somewhat
similar situation. API Grade SJ allows wear of 120 microns during this
test, while SM allows only 90 microns. I don't see any other test that
seems related to zinc content.
Randall
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