[Healeys] Oil article abour ZDDP

M Lempert mlempert at bellsouth.net
Wed Feb 6 09:36:27 MST 2008


Robert et al:  What I think I was trying to convey was my simple approach to 
this confusing issue.  While some folks do take enjoyment from digging 
through the data for a thorough understanding, I prefer finding a simple 
solution that will keep me out of trouble.  While just about every facet of 
this has exceptions, there are some simple rules that will help avoid 
problems. For instance, I will avoid any oil rated "M" or later. Knowing 
nothing more, "L" or earlier is safer if you're in a spot and need to select 
something.  When in doubt, add an appropriate amount of EOS or STP (red or 
blue - I don't remember, but it is important to choose the right one). I 
have taken from the LN Engineering site a ratio as follows: "By our
calculations, between .5 and .66 oz of GM EOS has to be added to each quart
of oil to raise the Zn and P by 100 ppm each." .  I don't know if STP is the 
same or not.

As a regular oil choice for your shelf, oil changes, on-board supply, choose 
one that you're comfortable with and trust and stay with it - but keep your 
eye on the API rating should it ever change.

I had been okay with Valvoline VR1 Racing oil until I saw that it had the 
double SL/SM rating. The fact that SM showed up on the label to me implies 
something must have changed. I did see that the spec sheet says "ashless". 
Well, I don't want to find out someday that we need ash.  I'm going with 
Brad Penn. In a pinch I'll add some ZDDT to something else. There are other 
good choices, I'm sure.

Regards,
Mike Lempert

From: "Robert Blair" <rnbmail at yahoo.com>
Sent: Tuesday, February 05, 2008 8:27 PM
Subject: Re: [Healeys] Oil article abour ZDDP


> Hi listers, The beat goes on on the oils discussion - interesting
>
> [First appologies - VR1 is of course Valvoline - not Chevron]
>
> Second, oil is a competitive market, and is just another target for
> confusing and in many cases false advertising. Most consumers are not
> chemists or metalurgists and so the marketing message has to be reduced
> to a very few simple codes.
>
> The catalytic degredation by Phosphorous is real, and so the downward
> trends of ZDDP levels is justified for newer engines with newer design
> tolerances and metalurgy, plus huge cats.
>
> So for us older folks with older engines we must maintain 'adequate'
> levels of zinc - metal surfaces are not as tolerant/smooth and the
> tolerances/gaps are designed to be larger.  Adding to the problem is
> that weighs have dropped to match the smaller tolerances - typically
> 5W30 for a modern engine - adding to the tolerance/gap problem of older
> engines.
>
> My take - keep the weight up, make sure there is 'enough' on board
> ZDDP, or add 'enough' ZDDP to a modern cat saving oil, change often.
>
> Robert.


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