looking for 20w50 with cat friendly ZDDP

[rubberchicken]

TL;DR- in search of cat friendly 20w50 and 10w40.
I am buying a newerish boat - 2018 with twin Mercruiser 502 engines that have cats. On my previous boats with 454's and no cats I used AMSOIL Premium Protection 20w50 with great success. It also has a Kohler 7.5 EKD generator with the Kohler Command PRO LH690 engine, again with a cat. For my previous Kohler generators that used the Kawasaki water cooled vtwin I used Amsoil 10w40. So now I am looking for a gas 20w50 with cat friendly ZDDP levels, and also a 10w40 with cat friendly additives. I found that the Mercruiser / Quicksilver recommended oil which is a 25w40 semi-synthetic does not appear to be cat friendly with zinc around 800 and phosphorus around 800, but the limited VOA on this oil are 3-5 years old. My personal preference is to avoid the Merc/Quicksilver oils as I consider them overpriced and underwhelming.

So are the Amsoil Premium Protection 20w50 and 10w40 products low enough in zddp to be cat friendly ? Also open to other products, although I have 2-3 gallons of the 20w50 on the shelf and would prefer use it.

 

[JavierH19]

How much does it burn. If there's no consumption then theres no harm. But at the same time many engines like my sierra will burn some oil but still be on the original cat 300k later so if yours burns but it's not used every day then it won't matter much. Also i doubt there's emissions inspections on boats so who will stop who.

 

[Japanese]

So now I am looking for a gas 20w50 with cat friendly ZDDP levels, and also a 10w40 with cat friendly additives.

Here two budget friendly options.

Valvoline Advanced Protection 20W-50 (the typo 20W-20 still stays after more than 6 monts)
Note: It comes only in quart bottles and mostly available online.
https://www.valvolineglobal.com/en/advanced-full-synthetic-sae-20w-50/

PDS
https://sharena21.springcm.com/Publ...2d889bd1/b545b08d-9553-ea11-9c34-ac162d889bd1

Valvoline MaxLife 10W-40
https://www.valvolineglobal.com/en/high-mileage-max-life-motor-oil-sae-10w-40/

PDS
https://sharena21.springcm.com/Publ...3793b338/aeb45538-251b-eb11-b7fc-48df3793b338

 

[billt460]

......... Also i doubt there's emissions inspections on boats so who will stop who.

This ^^^^^^^^^^^^^^

 

[rubberchicken]

The engines burn no appreciable oil and only have 105 hours on them. The cats are in a cartridge that can be removed from the water-cooled exhaust manifold, but are still tracked by the engine computer, so it safe to assume warning error and the danger of limp mode could occur if they were removed..

 

[gman2304]

IIRC Valvoline Vr1 conventional 20w50 is cat safe.

 

[altaylar]

Valvoline AP 20w50 is the way to go.

Though sounds like you could use a high P oil for a very long time before you would have an issue with your cats. I would remove them after clogging them up, which will likely never happen

 

[PontiacHO]

I’d bet the owner’s manual calls for Quicksilver 25w50. Why not?

 

[Hohn]

IIRC Valvoline Vr1 conventional 20w50 is cat safe.

Right, but why not use the synthetic?


HPL makes a PCMO 20w-50 with a dexos-based adds pack that meets api SP. I’d consider that for this application.

 

[fantastic]

API SP

 

[kschachn]

The engines burn no appreciable oil and only have 105 hours on them. The cats are in a cartridge that can be removed from the water-cooled exhaust manifold, but are still tracked by the engine computer, so it safe to assume warning error and the danger of limp mode could occur if they were removed..

Then there isn’t a worry.

 

[Lawnman23]

IIRC Valvoline Vr1 conventional 20w50 is cat safe.

https://www.valvolineglobal.com/en/vr1-racing-motor-oil-sae-20w-50/

 

[D1dad]

If you’re not using oil what’s the worry? Hpl or XPR. With that type of power plant I wouldn’t skimp. I had a car that burnt a qt every 1k and the cats never went out….shockingly.

 

[kschachn]

View attachment 333276

https://www.valvolineglobal.com/en/vr1-racing-motor-oil-sae-20w-50/

But if the ZDDP isn't getting there then it is not a concern. The one time I saw a catalyst efficiency code in a car was one where the guy was using a relatively high ZDDP oil and was burning in excess of 1 quart in 500 miles. It takes quite a bit to poison the catalyst.

 

[Lawnman23]

But if the ZDDP isn't getting there then it is not a concern. The one time I saw a catalyst efficiency code in a car was one where the guy was using a relatively high ZDDP oil and was burning in excess of 1 quart in 500 miles. It takes quite a bit to poison the catalyst.

Yep, I agree. I was just posting Valvolines official disclaimer regarding it.

To your point, if VR1 is safe for cats, essentially any 20W-50 will be. Or any other oil for that matter.

 

[Nessism1]

TL;DR- in search of cat friendly 20w50 and 10w40.
I am buying a newerish boat - 2018 with twin Mercruiser 502 engines that have cats. On my previous boats with 454's and no cats I used AMSOIL Premium Protection 20w50 with great success. It also has a Kohler 7.5 EKD generator with the Kohler Command PRO LH690 engine, again with a cat. For my previous Kohler generators that used the Kawasaki water cooled vtwin I used Amsoil 10w40. So now I am looking for a gas 20w50 with cat friendly ZDDP levels, and also a 10w40 with cat friendly additives. I found that the Mercruiser / Quicksilver recommended oil which is a 25w40 semi-synthetic does not appear to be cat friendly with zinc around 800 and phosphorus around 800, but the limited VOA on this oil are 3-5 years old. My personal preference is to avoid the Merc/Quicksilver oils as I consider them overpriced and underwhelming.

So are the Amsoil Premium Protection 20w50 and 10w40 products low enough in zddp to be cat friendly ? Also open to other products, although I have 2-3 gallons of the 20w50 on the shelf and would prefer use it.

800 ppm with a 20W-50 is relatively low. Many oils of this grade are higher. It seems you are overthinking.

 

[OVERKILL]

I found that the Mercruiser / Quicksilver recommended oil which is a 25w40 semi-synthetic does not appear to be cat friendly with zinc around 800 and phosphorus around 800, but the limited VOA on this oil are 3-5 years old. My personal preference is to avoid the Merc/Quicksilver oils as I consider them overpriced and underwhelming.

That level of phosphorous (800ppm) is exactly what the API limit on the RC grades is, for "catalyst protection", a limit imposed because of the expectation that these oils may be consumed faster than a keg at a frat party. There is no limit on heavier grades (xW-40 and above) because they are less likely to be consumed.

You are vastly over-thinking this. Your primary focus should be on AW and corrosion protection, the phosphorous level, unless the engines are burning a quart per outing, isn't a concern.

 

[JavierH19]

800ppm especially in new additive packs is fine if we're honest. For the longest time i was hardline high ppm counts but i've learned a lot over the years. And if anything an 800ppm pcmo sq ap will very likely outperform an older sm/sn ap with 1000-1100ppm. Mobil's additive packs are 600ppm but seem to protect great even in thin grades.

Viscosity is still the main mechanism for preventing wear but zddp/phos and other additives are there to step in when needed. It's also why I think anti foaming agents contribute greatly in wear prevention as an oil with a fabulous ability to prevent foaming/bubbling like HPL will have an unbroken film of oil and no cavitation even in the worst of scenarios while an oil that doesn't do great like rotella can risk having cavitation in the bearings where there's supposed to be a uniform high pressure layer of oil and puts a lot more burden on the additive pack.

At the end of the day using a good oil like Mobil 1 15w-50 or the full syn 15w-40's from valvoline, mobil, and chevron and not rotella which i wouldn't use at least until they update the formulation for CL next year would be what i'd do and i'd change it every year of 100 hours.

 

[OVERKILL]

800ppm especially in new additive packs is fine if we're honest. For the longest time i was hardline high ppm counts but i've learned a lot over the years. And if anything an 800ppm pcmo sq ap will very likely outperform an older sm/sn ap with 1000-1100ppm. Mobil's additive packs are 600ppm but seem to protect great even in thin grades.

Viscosity is still the main mechanism for preventing wear but zddp/phos and other additives are there to step in when needed. It's also why I think anti foaming agents contribute greatly in wear prevention as an oil with a fabulous ability to prevent foaming/bubbling like HPL will have an unbroken film of oil and no cavitation even in the worst of scenarios while an oil that doesn't do great like rotella can risk having cavitation in the bearings where there's supposed to be a uniform high pressure layer of oil and puts a lot more burden on the additive pack.

At the end of the day using a good oil like Mobil 1 15w-50 or the full syn 15w-40's from valvoline, mobil, and chevron and not rotella which i wouldn't use at least until they update the formulation for CL next year would be what i'd do and i'd change it every year of 100 hours.

I'm still waiting for Mobil to update their ZDDP guide on what these values are supposed to be, because I know we've seen some considerable deviations from the values Mobil states when compared to VOA's on oils that the guide was current for (it is a bit dated right now as you know, not updated for SQ yet). I had to have OAI/Polaris re-run my HPL sample because the values were low, so this doesn't seem to be unusual.

 

[rubberchicken]

Looking at Amsoil 20w50 the zddp is around 1500 ppm, which makes me think is not very cat friendly. I got this from a VOA on BITOG for Ams 10w40 which I think has the same additive pack. I would prefer to stick with synthetic oils, so I ruled out VR1. The Mercruiser oil is nothing special and they charge $15 or more a quart.