Quaker State Defy vs ZDDP additive

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I need to change the oil in my '79 Trans Am with the stock Pontiac 400 engine. Was going to use Pennzoil High Mileage and add a bottle of the new Edelbrock ZDDP (zinc & other old-school additives) to it. I've read a lot of horror stories about old musclecar motors breaking down due to the newer oils not having the levels of zinc and other additives that oil used to have to help cars with flat tappet cams, etc., but those additives were removed in the name of pollution control. Now I see that Quaker State's Defy 5W-30 advertises added zinc and low wear. That's what I want! But apparently they don't make it in 10W-40, or if they do, it's not sold around here. Which is better for my T/A, QS Defy or Pennzoil High Mileage with a bottle of ZDDP? Or do I need to be worried about zinc for this car?
 
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Agreed. Also did I read stock. I do not think you need extra ZDDP and defy VOA did not seem to have loads and loads of ZDDP as many thought. I do not believe extra ZDDP is needed in this application. But if you are losing sleep over it just use a 10W-30 HDEO.
 
Originally Posted By: dave1251
But if you are losing sleep over it just use a 10W-30 HDEO.


That's the easiest answer, and a wise choice. Defy may be good, and I'm itching to try it in my old truck. I'd like to see more VOAs on it, though.

ZDDP additives can be fine, but when you add the price of a PCMO conventional (or HM in your case) and the additive, it likely will be way above what a sump load of 10w-30 HDEO would cost. Mobil Delvac 1300 10w-30 or Rotella 10w-30 would have sufficient ZDDP for most purposes.
 
The Walmart here has Defy in 10W40. Maybe your Walmart can order it for you. Pennzoil GT has something like 1300-1400ppm of zddp. It`s only made in 25W50 or SAE60 though (I think). Oreilly can order it. But a 50 weight may be perfect for your GM 400. Alot of people use 20W50,etc from what I`ve read on various musclecar forums.
 
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As mentioned above, the one VOA I've seen for Defy appeared to be more hype than substance. Time will tell. You'd be better off IMO with an HDEO which was also suggested, Rotella 10w30 is a thick 30, if you really need a 10w40 I spotted Rotella T5 10w40 at Tractor Supply, only place I've seen it.
 
I was also disappointed in the amount of zddp in the QS Defy VOA that was posted here a while back. I think your plan of adding a zinc supplement to a quality, readily available oil is fine. It adds maybe $12 to the cost of an oil change, but it's cheap insurance over having to rebuild an engine.

http://www.zddplus.com/

Also, check out the above link. ZDDPlus has a lot of articles on their website about using zinc supplements versus other options for protecting slider-follower valvetrains.
 
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Originally Posted By: A_Harman
Also, check out the above link. ZDDPlus has a lot of articles on their website about using zinc supplements versus other options for protecting slider-follower valvetrains.


We've all read that, but they gloss over a couple things. One, they're selling a product. Telling people to buy an HDEO, or Amsoil, or RP HPS, M1 racing, or Valvoline VR-1 cuts into their profit margins.

Secondly, although this was written in 2008, they claim limited viscosity choices for HDEO and no ILSAC rating. Well, do they want an ILSAC rating (with a corresponding reduced phosphorus content) or don't they? They can't have it both ways. As for viscosities, are they sure they didn't write this based upon 1988 oil choices? For HDEOs, there are 0w-30s, 5w-30s, 10w-30s, 0w-40s, 5w-40s, and 15w-40s readily available, under various Cx/Sx specifications. ZDDP levels are sufficiently high, and independent evidence of this abounds.

To them, HDEOs have too much detergent and this inhibits the effectiveness of ZDDP. I have no idea whether or not this is true. They cite one study, which has no link, and I haven't happened to come across to check it out. They mention energy conserving oils and viscosity choice, again, with respect to fuel economy. Does the price of their product added to the price of a PCMO save enough gas to make it a better option than, say, Rotella 10w-30?

Then, they claim that racing oils have too little detergent. We already know that. If it's a garage queen, does it matter? If it's never driven hard in the first place, does the ZDDP level matter much anyhow?

I don't claim that ZDDP supplements are ineffective or are inferior products. I've used Comp Cams additive, and still have a couple bottles left. It's far from the only option, however.

My view is that the people who would benefit most from a ZDDP additive (both for engine protection and financially speaking) are a rather niche market. Someone with an extremely high performance engine that tends to be driven only rarely and driven hard (i.e. weekend tracking, time trials, and so forth) would be best served by a racing oil. Someone who has an older, yet relatively mild engine that's driven regularly (i.e. as a daily driver) would do fine with HDEO or something like Defy (or even SN/GF-5 PCMO, for that matter). If you're running a high horsepower late 1960s/early 1970s high performance American car as a daily driver, then I can see the cost and protection benefit of a modern PCMO with a ZDDP additive. In this scenario, it would be far cheaper than a boutique oil with enhanced ZDDP levels.

I apologize for being so long winded about this, but old flat tappet engines see vastly different usage and maintenance regimens, with no warranty constraints, and there is no one size fits all answer with respect to return on investment. Lots of guys with older Jeeps run HDEOs with no cam problems. Also, lots of Chevy guys have run small blocks with high ZDDP oils and still saw cams get rounded out. I know; I'm one of them.
 
Originally Posted By: MaverickZ71
I need to change the oil in my '79 Trans Am with the stock Pontiac 400 engine. Was going to use Pennzoil High Mileage and add a bottle of the new Edelbrock ZDDP (zinc & other old-school additives) to it. I've read a lot of horror stories about old musclecar motors breaking down due to the newer oils not having the levels of zinc and other additives that oil used to have to help cars with flat tappet cams, etc., but those additives were removed in the name of pollution control. Now I see that Quaker State's Defy 5W-30 advertises added zinc and low wear. That's what I want! But apparently they don't make it in 10W-40, or if they do, it's not sold around here. Which is better for my T/A, QS Defy or Pennzoil High Mileage with a bottle of ZDDP? Or do I need to be worried about zinc for this car?


Well, I'll be trying QS Defy in my '80 Firebird FORMULA after using MaxLife for the past 3 summers/OCI's.

I have seen the QS Defy in 10W40 at my local W*M so, I know that it's around.

I won't be using the QSD for it's ZINC as I will for it's HM benefits as I have with the MaxLife. The ML has slowed down my leaks considerably.
 
Originally Posted By: chevman4life
Where can you find Delvac 10W30?


You may have to check with your XOM bulk dealer, or go the route of Rotella 10w-30. My Imperial Oil (our XOM) bulk dealer told me he has Delvac 10w-30 in stock when I went to check on the old, discontinued Esso XD-3 5w-30.
 
Originally Posted By: chevman4life
Where can you find Delvac 10W30? I might try that in my old truck but have never seen it.


I looked once upon a time, I don't think it's available in anything smaller than a 5 gallon pail.
 
I believe you're right, but that size would work just dandy for me. Since I've been known to stash oil, four 5 quart jugs, five 1 gallon jugs, or one 5 gallon pail makes no difference to me. Since my old truck takes 6 quarts, the pail is probably the most convenient anyhow.
 
My O'Reilly's will order the 10W-30 Delvac for me

Do it quick. There is a $5/$25 MIR on gallon/pail until the end of the month.
 
I prefer to buy an oil that already has high ZDDP. That is because some oil additives that contain extra ZDDP might not have as much detergent or anti-foam additves that are also important, and might have a different viscosity from just buying oil with high ZDDP.

I have heard the theory that the high detergent content of HDEO lowers the effectiveness of the high ZDDP, however, I see really good UOA results from using HDEO in a gasoline engine.
 
Quite right. We tend not to know the viscosity of these ZDDP additives, nor much else about their makeup. Besides, the HDEOs we're looking at are dual rated. I still would like to give Defy a shot yet.
 
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