I'm gonna link a site in a sec, but here are some tidbits:
Most major oil companies say to NEVER EVER add anything to their oils, because doing so will upset the oil’s carefully balanced additive package that was designed by their Chemical Engineers. I tested doing that very thing in several different oils, and found that adding zinc additives in every case, ruined the oils by SIGNIFICANTLY REDUCING their wear protection capability. That of course, is just the opposite of what people “think” they will be getting. So, those major oil Companies were absolutely correct about not adding anything to their oil. And people who insist on choosing an oil based on zinc level alone, are very likely shooting themselves in the foot, and ending up with far LESS wear protection than they THINK they have. It just depends on which particular oil they select. A number of popular traditional high zinc oils have proven to provide poor wear protection when actually put to the test.
I’ve also tested ZDDPlus zinc additive in 3 low zinc oils, and I’ve tested Edelbrock Zinc additive in 3 different low zinc oils. In each case, the recommended amount of additive was used. And in all 6 cases, these high zinc additives ruined the oils and made them WORSE than they were before the extra zinc was added, by SIGNIFICANTLY reducing their wear protection capabilities. These additives did the opposite of what was promised. That is not surprising, because most major Oil Companies say to never add anything to their oils, because doing that will ruin the oil by upsetting the carefully balanced additive package that their Chemical Engineers designed into them. And that is precisely what was seen when using these high zinc additives.
ZDDPlus” added to O’Reilly (house brand) 5W30, API SN, conventional = 56,728 psi
zinc = 2711 ppm (up 1848 ppm)
phos = 2172 ppm (up 1356 ppm)
moly = 2 ppm (up 2 ppm)
The amount of ZDDPlus added to the oil, was the exact amount the manufacturer called for on the bottle. And the resulting psi value here was 38% LOWER than this oil had BEFORE the ZDDPlus was added to it. Adding ZDDPlus SIGNIFICANTLY REDUCED this oil’s wear prevention capability. Just the opposite of what was promised.
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193. “ZDDPlus” added to Motorcraft 5W30, API SN, synthetic = 56,243 psi
zinc = 2955 ppm (up 1848 ppm)
phos = 2114 ppm (up 1356 ppm)
moly = 76 ppm (up 2 ppm)
The amount of ZDDPlus added to the oil, was the exact amount the manufacturer called for on the bottle. And the resulting psi value here was 12% LOWER than this oil had BEFORE the ZDDPlus was added to it. Adding ZDDPlus SIGNIFICANTLY REDUCED this oil’s wear prevention capability. Just the opposite of what was promised.
Taken from here: (good reading, by the way of some really good oil performers as far as wear protection)
https://540ratblog.wordpress.com/2013/0 ... t-ranking/
I'll save you a lot of headache and post the top ten:
The Wear Protection reference categories are:
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• Over 105,000 psi = INCREDIBLE wear protection
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• 90,000 to 105,000 psi = OUTSTANDING wear protection
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• 75,000 to 90,000 psi = GOOD wear protection
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• 60,000 to 75,000 psi = MODEST wear protection
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• Below 60,000 psi = UNDESIRABLE wear protection
1. Prolong Engine Treatment added to 5W30 Pennzoil Ultra, API SN synthetic = 136,658 psi
This oil on its own WITHOUT the Prolong Engine Treatment added to it, has a wear protection capability of 92,569 psi. With the recommended amount of Prolong added per qt, its wear protection capability “WENT UP 48%”.
The data here provides information on wear protection capability, but does NOT provide any information as to how compatible this product’s chlorine may be with a given oil’s additive package. Chlorine and additive package incompatibility has a possible risk of creating damaging bearing corrosion problems. There have been legal issues with this product that you can Google for yourself. Contact Prolong’s maker for more information on compatibility, to find out if it is safe to use in your application. The test data on Prolong is included in my Ranking List for informational purposes only, because of requests I have received about testing this product. But, I do not endorse nor recommend its use. It is always best to simply choose a highly ranked oil in the first place, and avoid using any aftermarket additives at all.
2. Prolong Engine Treatment added to 5W30 Castrol GTX, API SN conventional = 130,366 psi
This oil on its own WITHOUT the Prolong Engine Treatment added to it, has a wear protection capability of 95,392 psi. -
No longer available without ultraclean which drops its rank badly to 78,664 psi
3. 0W40 Mobil 1 “FS” European Car Formula, ACEA A3/B3, A3/B4, API SN, synthetic = 127,221 psi
4. 0W20 Quaker State Ultimate Durability, API SN, synthetic (gold bottle) = 124,393 psi
5. 5W30 Valvoline Full Synthetic High Mileage with MaxLife Technology, API SN, GM dexos 1 approved (silver bottle) = 123,470 psi
6. 5W30 Pentosin Pento Super Performance III, for gas and diesel engines, API S”M”, ACEA C3, synthetic, made in Germany = 122,711 psi
7. 5W20 Quaker State Ultimate Durability, API SN, GM dexos 1 approved, synthetic (gold bottle) = 121,396 psi
8. 0W30 Gulf Competition, High Performance Racing Engine Oil, ester-based synthetic = 119,789 psi
9. 5W30 Mobil 1, Advanced Full Synthetic, API SN, GM dexos 1 approved = 117,799 psi
(This is the one I use in my LS1 engines)
10. Prolong Engine Treatment added to 5W30 Pennzoil, API SN conventional (yellow bottle) = 117,028 psi
This oil on its own WITHOUT the Prolong Engine Treatment added to it, has a wear protection capability of 76,989 psi.
Top conventional oils include:
For my benefit when I switch next oil change....
5W30 Pennzoil High Mileage Vehicle, API SN, conventional = 102,402 psi
High Mileage oils are formulated for older engines with over 75,000 miles on them. And High Mileage oils include “Seal Swell” chemicals to help reduce oil leakage in those older engines.
5W30 Chevron Supreme, API SN conventional (blue bottle) = 100,011 psi
10W40 Pennzoil High Mileage Vehicle, API SN, conventional = 97,419 psi
20W50 Castrol GTX, API SN conventional = 96,514 psi
5W30 Havoline, API SN conventional = 95,098 psi