Ted can verify, but I think it is any SM single viscosity or dual viscosity above 30, 10w40, 20w50, etc and any SM oils identified as racing or high mileage. Again, lot's of options. Some oils even have something like for older engines or for flat tappet engines on the bottle.

Your castrol 20w50 should be just fine with no additive. I don't know, but often, too much of a good thing is bad. I'd find out if there is such a thing as too much zddp with the additive. I use valvoline VR1 and if I can't find that, regular Valvoline. 20w50 for both, no additive.


Lawrenceville, GA

As Charlie brings up, too much ZDDP creates a situation called ‘zinc overloading’. The excess of zinc can cause pitting on the cam lobes which then leads to premature cam wear.

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But regarding the rest of this conversation, I’ll try to make this as politically correct as possible but the zinc reduction mandate in the oils technically belongs in the same category as ethanol laden gasoline. jmo.

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Unfortunately the U.S. has some over-zealous politicians that took it upon themselves to mandate the reduction in zinc/phosphorus content without examining existing recent data regarding the actual residuals that gets past the piston rings. This reduction was part of the mandate to increase the life span of the catalytic converters. It’s actually not the zinc that’s an issue but the phosphorus which is attracted to high heat sources and the zinc simply follows and transplants itself on those high heat (friction) locations. Without the phosphorus content in the oil, the zinc doesn’t work. It is the phosphorus that’s considered to be a detriment to the catalytic converters and as such, the ZDDP content in the oils being used by the new car manufacturers has been reduced. With the latest API-SN oil classification, the gasoline engine rated oils remained unchanged but the diesel oils have also gone through a zinc content reduction. Reading in detail the latest API bulletin will explain which oils have what in regards to zinc/phosphorus contents. With oil control as good as it is on the modern cars, reducing the zinc/phosphorus content in the oil is a bit of overkill.

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Here’s a link to a past thread regarding oils

http://forums.y-blocksforever.com/FindPost76853.aspx

Lorena, Texas (South of Waco)

I notice that some of the high grade oil (and expensive) over here has zinc + boron listed as the main anti-wear additives. What are your thoughts on that?

http://www.penriteoil.com.au/pis_pdfs/10%20TENTHS%20PREMIUM%205%20SEPTEMBER%202013.pdf

Here is a link to their site.