I was considering the reduced zinc content in oil a few weeks ago when I replaced the timing chain tensioner in my 1600 engine.
Would the reduced zinc cotent affect the wear of the timing chain tensioner pad (hard plastic)?
 
 

ZDDP additive?

From here -
 
oils with a CG and higher rating typically don't contain enough ZDDP, and the replacement friction modifiers don't work in highly loaded valve trains (generally older engines especially those with 2V design). If you try to compensate by adding a ZDDP additive into a newer oil it still might not work because of interactions with other additives in the oil.

and I thorght it was going to be easy

fordsy

Here's the advice from my engine builder who put my pinto bottom end together which i'll be taking over pretty much anyone else out there.

"oil needs to be a mineral based 20W/50, 25W/50 or 25W/60 NO synthetic can be used."

+1 for that too. My engine builder said the same. Oh hang on, it was the same guy. 
 
Without trying to sound like an ad for Castrol I use Edge 25W50. It's cheap and it's for old school cars. (replaced the old GP50 formula)
http://castroledge.com.au/oils/25w-50

This table from Penrite (Feb 2009) lists the zinc content of their oils:
 
http://www.penriteoil.com...ST%20ZINC%20LEVELS.pdf
 
and another here with other brands:
 
http://www.jeepfan.com/te...-know-about-motor-oil/
 

Hmmm, some of that data is contradictory, or rather the formulations may have changed.  The Penrite link I gave above shows HPR30 having 0.158% zinc, whereas Penrite's datasheet for it says 0.11%.
 
http://www.penriteoil.com...hpr_30_premium_mineral
 
HPR15 is reduced too, being 0.114% in the datasheet:
 
http://www.penriteoil.com...%2015%20AUG%202012.pdf

I use the Castrol Edge 25-50W in my good engines, and KMarts KMX brand oil in all others.   BOTH hold very good oil pressure when hot and do not damage the engine....  I used a Shell Helix (yellow) once a number of years ago and that engine had negligible pressure when idling at the end of a sprint, whereas even the KMX still keeps virtually the same pressure very hot (in the worked autocross car) as it does at normal temps.  I did use a Mobile 1 full synthetic for a few years, but it is too thin for a Pinto and runs away from the cam spray bar when cold.  Didn't seem to do any damage, but I did notice that it took a little while on startup to build the pressure and it was a little lower than the heavier oils.
 
Everyone has their own personal preference for oil (some cheap and some expensive), but it should be for the original specifications for the engine and not a re-refined oil (they break down too easily) and something that does not damage you engine.  (I won a bottle of Helix in a raffle a few years ago and gave it away, as I would not even use it on a road engine after what it did)  If you have spent money on your engine and give it more than normal road duties, then you need to have a close look at what it is doing to your oil pressure/engine internals.....

Had the head on my Pinto converted to unleaded recently and the mechanic advised he used Penrite 30, highly recommended it for older engines...

Penrite hpr30
use it both in the race car (Lotus Twincam)and the rally car (pre-crossflow)
cant beat it
 
Ted