> From
> the start in Florida until we reached about the near halfway point in
> Tennessee, the car was running Valvoline 20W/50 with added
> ZDDP. At the next
> change, I was recommended to switch to Valvoline VR1 Racing
> 40. On reaching
> Colorado, where we did an equivalent 10,000 mile service, the
> cam chambers and
> oil filter were full of an odious black sludge.
That's curious, John, I wonder what happened. I have covered many thousands
of miles with both 20W50 and straight 40 VR1, and never seen anything like
you describe. The oil itself would eventually turn dark, but the inside of
the engine would be very clean.
I have to think that the ZDDP additive was at least partially to blame.
-- Randall
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