looking for 20w50 with cat friendly ZDDP

[OVERKILL]

That is a huge help- but steers me back to the original question should not be "what API level" but "what level of phosphorus is harmful given average oil consumption, on a 10w+ or higher oil". But its not an AI error, rather an error in my question. Is this a correct question for my use case ?

Euro applications now use GPF's and DPF's, which are far more sensitive to phosphorous poisoning than conventional catalysts. They limit phosphorous to 900ppm, which, oils like Mobil 1 ESP X3/X4 0W-40 are right at, in terms of amount included.

You don't have a GPF.

Non-GPF Euro applications have historically called for a full-SAPS lubricant, which tend to range in phosphorous levels from 900-1,100ppm. That would be the range you should be targeting.

 

[rubberchicken]

I’d also bet that it’s “expensive “ for good reason. It’s a marine specific oil. If you’re going to bat down even the manufacturer’s recommended oil, then don’t post for help then challenge the others here offering suggestions. Catalytic converter issues due to zinc are the result of worn out oil burning junk. Converters never “clogged” due to zinc 25 years ago with well maintained engines (non oil burning).

There has been occasional VOA of this Quaker State 25w40 oil, and it has been shown to be nothing special over the last 10-15 years. So I do not have any reason to think its radically changed recently. My quest is an alternative to the Quicksilver 25w40 oil as I stated in my original post.

 

[kschachn]

I’d also bet that it’s “expensive “ for good reason. It’s a marine specific oil. If you’re going to bat down even the manufacturer’s recommended oil, then don’t post for help then challenge the others here offering suggestions. Catalytic converter issues due to zinc are the result of worn out oil burning junk. Converters never “clogged” due to zinc 25 years ago with well maintained engines (non oil burning).

I agree. If that was my expensive boat and my expensive engine that’s the oil I’d use.

However, it’s not the zinc it’s the phosphorus, and it doesn’t clog converters, it poisons the catalyst. But as you note only if it gets there, and in relatively large amount.

 

[kschachn]

There has been occasional VOA of this Quaker State 25w40 oil, and it has been shown to be nothing special over the last 10-15 years. So I do not have any reason to think it’s radically changed recently. My quest is an alternative to the Quicksilver 25w40 oil as I stated in my original post.

Cheap $35 spectrographic analyses are not a reliable predictor of future performance.

 

[rubberchicken]

Cheap $35 spectrographic analyses are not a reliable predictor of future performance.

There are plenty of oils out there that meet the NMMA FW-C standard, and the Quaker State 25w40 has a reputation in the hi-performance marine industry as just being average, while being very high priced. I would rather not use it.

 

[rubberchicken]

That is my main worry- slowly poisoning the cats, not clogging them.

 

[rubberchicken]

I had a talk with Amsoil today, and got the specs on a bunch of different oils.
This is the 20w50 ARO
AROQT

BORON	0
SODIUM	0
MAGNESIUM	0
CALCIUM	3614
PHOSPHORUS	1258
ZINC	1384

 

[Japanese]

That is my main worry- slowly poisoning the cats, not clogging them.

How much of Amsoil Premium Protection 20W-50 do you have?
Why don't you call Amsoil and ask them?

Here's that oil PDS. https://amsoilcontent.com/ams/lit/databulletins/g2212.pdf

Specification:
API SL (same as Valvoline VR1), SJ, SH, SG
API CI-4+, CI-4, CH-4, CF, CF-2
ISO-L-EMA
Caterpillar* ECF-1
JASO MA (Motorcycle)
MAN* 271/3275
MTU Type 2
Cummins* 20071/20072/20076/20077
Volvo*, VDS-2, VDS
Mack* EO-M+, EO-M
ACEA A3/B3, E3, E5
MB 228.1, 228.3, 229.1
Detroit Diesel* 93K214

Looking at the approvals it looks like a diesel oil to me. It's full-SAPS and is no suitable for GPF and DPF, but that doesn't mean that it will Poison your cats, if you use it once or twice.

 

[Nuclear_42]

The GM 502 and the Mercruiser variant have hydraulic roller cams. No need to worry about getting ZDDP levels of yesteryear. The ZDDP formulation in modern API oils will be more than adequate for this engine. Feel confident with any xW-50 oil.

I'd personally be happy with a 5W-50. Amsoil or HPL would get my vote.

Amsoil XL 10w40 is very robust. On paper much better than the 5w50 SS. I did some research on a similar scenario for a friend classic car. HTHS and CST.

 

[OVERKILL]

There are plenty of oils out there that meet the NMMA FW-C standard, and the Quaker State 25w40 has a reputation in the hi-performance marine industry as just being average, while being very high priced. I would rather not use it.

If you aren't afraid to spend, which it seems you aren't, give Dave at @High Performance Lubricants a call and ask for their recommendation for your specific application, they'll either have something in stock or they'll make something for you.

 

[rubberchicken]

That sounds like an interesting idea !!

 

[cheech279]

It's not easy to find, but Kendall GT Performance 20w-50 still carries the SP and SN+ ratings even with the zinc content at 1,200.

 

[BrendanC]

If you aren't afraid to spend, which it seems you aren't, give Dave at @High Performance Lubricants a call and ask for their recommendation for your specific application, they'll either have something in stock or they'll make something for you.

cannot second this enough. Dave will steer you right without over selling you. originally i was going to run our fleet on a euro 5w-30/40 and he told me not to waste money. he assured me the PCEO 5w-40 would do more than i am asking of it. he was right based off of used oil analysis.