whoops!
Sent that last post by mistake. Pressed send to soon.
But you can see that Royal Purple does have a high amount of additives
compared to other oils.
I really don't have a clue why they won't tell you the content when you
ask. If the figures on Bobs chart are correct, they should use it in
their advertising. Just some dumb corporate policy, unless something
changed.
Harley oil was mentioned, but that seems low by what we are comparing.
Is that oil suggested for all old Harleys or just the new design?
From my research anything under 1200 pm zinc is starting to get to the
marginal point.
I never answered Marty's question of what RP oil I was running.
It is the 20-50 Synthetic. It has a CF CF4 SJ rating. It is about 3-4
years old. I would have to check the new oils to see if the ratings
changed since then. According to Bobs chart it still has a moderate
level of ZDDP additive.
I think to make it easy on our cars, stick with any of the big brand
oils that have a Racing designation. They all seem to be very high, 1800
ppm and up of zinc. Next change I will step up to the RP Racing formula.
For most new cars stay with modern oils with the modern standards.
Joe Walters
73 H/O
