Quaker State with zinc added.

[Hib Halverson]

Quaker State Quote...
The use of ZDDP in motor oil has seen a gradual decline since 2001 in order to minimize or eliminate clogging of oxygen sensors and catalytic converters in modern cars due to volatile phosphorus. Prior to 2001, the typical concentration was roughly 1300 to 1400 parts per million (ppm) of ZDDP. However, since 2001, modern passenger cars have required oils with lower viscosity to reduce power loss and increase gas mileage, but achieving these lower viscosities with higher concentrations of ZDDP is difficult.
The proprietary low¿volatility ZDDP technology used in Quaker State Defy motor oil significantly reduces the amount of volatile phosphorus, while retaining its anti¿wear protective behaviour and antioxidant performance. Quaker State Defy has a ZDDP composition of 1200ppm, a more than sufficient amount to stand up to the most aggressive engine profiles.

What a bunch of marketing BS. Great reason to not buy Quaker State products.

First, ZDDP does not "clog" oxygen sensors nor cats. The phosphorous which results when ZDDP breaks down at high temperature at the lobe/lifter interface and then is burned by the engine during oil consumption, slowly reduces the potency of the catalytic reactant in a converter but it doesn't "clog" the cat. The EPA wanted cats to last 150,000 miles so it pressured the oil refining industry to reduce–but not eliminate–phosphorous from EP additive packages in engine oils for gasoline engines.

Second, phosphorous is not "volatile". It won't explode or burn rapidly. What an idiotic statement.

Third, the concentration of ZDDP has little or nothing to do with viscosity. You can have a 5W30 with 1200 ppm phosphorous and you can have a 15W50 with 800 ppm phos.

As for ZDDP being "used up" it is true that the EP additives in engine oils have a finite life as they are chemically broken down by the running engine in the lubrication process, however, this doesn't happen rapidly. If your oil change interval is 7500 miles, you might have a problem with inadequate EP lubrication at say 10,000 or 12,000 miles.

The information Shell offered is generally correct---for stock flat tappet camshafts and aftermarket cams with mild profiles and modest spring pressures 800-1000 ppm phos is plenty. Aftermarket cams with more aggressive profiles and higher spring pressures need 1000-1200. The most aggressive flat tappet cams running very high spring pressures need 1200-1400. I'll add that in odd applications, such as NASCAR Sprint Cup, which run incredible flat tappet cams, super high spring pressures and 9000+ rpm, besides oil with higher phosphorous concentrations, they're also using some pretty exotic parts such as tool-steel flat tappets and special camshafts.

You will find it sometimes can be difficult to find the phosphorous the actual content of some brands of oil.

 

[glen242]

I have been using Valvoline VR-1 10w-30 in my stroker with a CC XE274H cam since I built it, about 5 years ago. Prior to the stroker, I used VR-1 in my 350 with a CC 268H cam.

Never had a problem with either engine.

VR-1 has the Z and P that my flat tappet engines require. It also has a detergent package that lets it be used, on the street, with about 5000 mile oil changes. I only put on <2000 miles a year.

VR-1 is available through my local NAPA. If they don't have it in stock, they can order it in and it arrives in 1-2 days. I imagine other parts houses can do the same.

 

[Bolisk]

YIKES!!!

Just found out that regular Royal Purple. . .the stuff they sell in Autozone. . .etc. . .has been changed from SL to SN with much lower levels of ZDDP. I guess I cannot use regular Royal Purple any more. Note, royal purple makes an HPS version now. . .which does have plenty of ZDDP. . .but it's not readily avaiable in stores. Just though I should update my eariler post about Royal Purple.

 

[Hib Halverson]

I have been using Valvoline VR-1 10w-30 in my stroker with a CC XE274H cam since I built it, about 5 years ago. Prior to the stroker, I used VR-1 in my 350 with a CC 268H cam.

Never had a problem with either engine.

VR-1 has the Z and P that my flat tappet engines require. It also has a detergent package that lets it be used, on the street, with about 5000 mile oil changes. I only put on <2000 miles a year.

VR-1 is available through my local NAPA. If they don't have it in stock, they can order it in and it arrives in 1-2 days. I imagine other parts houses can do the same.

Typically VR-1 tests at about 1200 ppm phosphorous so, it is a very good petroleum-based engine oil.

 

[Evolution1980]

I'm sure Hib is able to summarize his own article, but the understanding I took away from it when I first read it some time ago, was that all the ILSAC, AP, and other ratings more or less referred to the amount of ZDDP in the oil, hence why you see oils marketed for "high mileage engines" without the ratings/certs. Since I'm only concerned about my engine and pretty much nothing else (I have no smog equipment), I usually buy the Mobil-1 full synth with the least number of certs listed, which is usually their "high mileage" oil. Wally World always has the best price...a 5qt jug for around $22-$24.

 

[Hib Halverson]

I'm sure Hib is able to summarize his own article, but the understanding I took away from it when I first read it some time ago, was that all the ILSAC, AP, and other ratings more or less referred to the amount of ZDDP in the oil, hence why you see oils marketed for "high mileage engines" without the ratings/certs. Since I'm only concerned about my engine and pretty much nothing else (I have no smog equipment), I usually buy the Mobil-1 full synth with the least number of certs listed, which is usually their "high mileage" oil. Wally World always has the best price...a 5qt jug for around $22-$24.

I'm not sure what you mean by the "least number of certs" but the only Mobil 1 5W30 or 10W30 which is suitable for use on OHV V8s with flat tappet cams in street-driven cars is "Mobil-1 High-Mileage". Whether or not Walmart sells it, I don't know.

 

[Evolution1980]

I'm not sure what you mean by the "least number of certs" but the only Mobil 1 5W30 or 10W30 which is suitable for use on OHV V8s with flat tappet cams in street-driven cars is "Mobil-1 High-Mileage". Whether or not Walmart sells it, I don't know.

I meant that Mobil-1's "high mileage vehicles" oil has the fewest (if any) ILSAC & API ratings/certifications.
WalMart carries it.

Mobil 1's page for the oil
Mobil 1 High Mileage 10W-30 Advanced Full Synthetic Motor Oil

Wally World's page
Walmart.com: Mobil 1 High Mileage 10W-30 Full Synthetic Motor Oil, 5qt: Automotive

 

[xfirez51]

As Hib points out, I am using Castrol GTX 15W-40 for diesel on my
LT-5 DOHC.

 

[Bolisk]

Yeah wall mart carries Mobile 1 10w30 High Mileage in tha 5 quart container for something close to $20. Great price.

The purolator classic oil filter they have there is nice as well.

 

[Hib Halverson]

As Hib points out, I am using Castrol GTX 15W-40 for diesel on my
LT-5 DOHC.

Well...Castrol 15W40 is certainly a good oil, but my comments about flat tappet camshafts don't apply to the LT5 because it's an OHC engine. I may have not made that clear in my posts to this thead but it is explained in the Engine Oil Deep Dive article elsewhere on the CAC.

The problems with insufficient phosphorous content in the oil and flat tappet cams come in engines with overhead valves, ie: pushrods and rocker arms. An overhead camshaft engine has much less load on the lifter/lobe interface and, thus, less need for EP additives in the oil.

With the exception of engines fitted with cams having very aggressive aftermarket profiles and valve springs with high spring pressure, LT5s do not need a special engine oil with higher levels of ZDDP.