I have already done a search here on LOST and can't find much in the way of discussion on ZDDP additives. What's the opinion of products like ZDDPlus?

I don't have an opinion. But, I just opened my newest oil analysis file and it had interesting results.
Previous test after 4,000 miles with Rotella T6 CJ-4 . . zinc at 1353

Amsoil AMO 10/40 CI-4 Plus (High Zinc Formula) . . . zinc at 1186 . . . after just 1500 miles. This oil is advertised for flat tappets, high performance, heavy duty. I expected the zinc to be at least 1400.

I had Blackstone run the Amsoil after 1500 miles to recheck sodium. I also thought for an oil that is advertised for 15,000 mile OCI, it might almost be like a VOA.

Just thought I'd throw this out. How can I decide about an additive with numbers like these. Judging by manufacturers claims, I would have guessed the RT6 to be a better candidate for a zinc additive.

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'05 Sport CRD 107k miles. NOBODY knows everything.

Well your CRD is not any of those so no you do not need it plus if you still have the cat on that extra zinc will damage it sooner then later.

Yes, but it's important to have it formulated into the oil with the correct balance of additives and detergents.

An interesting read:
http://www.lnengineering.com/oil.html

and pay particular attention to this question in the FAQ:
"Is there any potential problems with boosting the Zn and P in my API SM or CJ-4 oil or such a thing as too much ZDDP?"

My take away from this is to select an oil with an appropriate level of ZDDP and stay away from additives.

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Share your ideas freely at https://www.facebook.com/groups/libertydiesels/

I just tried Amsoil 5W40 Full SAPS Euro formula. I will post how I make out with Analysis.

Sent from my Nexus 7 using Tapatalk HD

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2006 Sport, GDE FT Eco Tune, Custom Trans Tune
2015 Ram 1500 Big Horn EcoDiesel, GDE Hot Tune

I like the idea of high zinc content but did not like the fact that most additives will dilute the oil too so went on ebay and ordered the ZDDP maxx a two Oz bottle will do..... now i need to wrap my head around which is better Lubri Molly MOS2 or ZDDP Maxx as additive pack to Delo 5W40 Synthetic oil.....

News about the lack of zinc in rotella has been greatly exaggerated

http://www.bobistheoilguy.com/forums/ub ... ost2566898

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05CRD: GDE Hot ECU & TCM tunes, Provent, Cat filter, Facet lift pump, TransGo kit, Florida TC, Samcos, stainless brake lines, HDS thermostat, Renegade light bar,
Bilstein adjustables, Al's Gen 4.5 Arms, 235/85-16 Duratracs, DTT rear, Elocker front, EVIC+TPMS, Turbo timer, McNally pillar gauges, Weeks Stage II kit.