W50 oil ratings. What's in your diesel?

Down2TheC · **Posted:** 29 Oct 2019 16:46

Past couple years I've noticed that my usual Penzoil HD30 first lost the HD and went to "SAE30" labeling, now I see they lost the CF rating from API that made it a good diesel oil. Checked the other brands and it's seemingly a trend. Everyone now lists the API SN rating which is great for cars of today but not great for 40yr old diesels. (or at least API doesn't say if an SN in a diesel will stand up to the high compression and general cleaning needs of a diesel.)

API site shows zero connection between the two ratings. CF should be on the bottom of the circular seal with the API ratings. SN, SF, etc go up top.

Only CF I see out there is Shell Rotella T1.

What are you folks putting in your diesel? And is the question itself overkill? I'm hoping an SN covers a CF but nobody wants to say that in official docs.

https://agriculture.mo.gov/weights/fuel/pdf/MotorOilsandLubricants.pdf
https://www.api.org/~/media/files/certification/engine-oil-diesel/publications/mom_guide_english_2013.pdf

cseltzjr · **Joined:** 16 May 2009 08:06 **Posts:** 254

I have been using Castrol 30 weight for the 20 years I have owned my W50. I don’t have a bottle handy to see the markings but that and the Fram $6.00 oil filter (again, I forget the number) every 50 hours or every fall.

WayneH · **Posted:** 29 Oct 2019 20:14

Since we got the boat in 2011, we've been using Shell Rotella in it. Same for the Honda cruiser motorcycles. Yeah, people go Huh? when you tell them that. But the wet clutches in the motorcycles don't mind. I've got 86K on my bike and the wife has 89K on hers.

Maineiac · **Posted:** 30 Oct 2019 12:57

Rotella. Only and always in all 30W applications. As to FRAM, I suggest watching a few youtube videos. The FRAM filters are pure garbage, and there's one on my W50 right now. WIX is the way to go. There's actually a filtration system in the WIX filters whereas the Fram filters are paper dolls. Literally.

puffcard · **Posted:** 30 Oct 2019 16:18

Maineiac wrote:

Rotella. Only and always in all 30W applications. As to FRAM, I suggest watching a few youtube videos. The FRAM filters are pure garbage, and there's one on my W50 right now. WIX is the way to go. There's actually a filtration system in the WIX filters whereas the Fram filters are paper dolls. Literally.

Agree with this 100%. NAPA Gold oil filters are made by WIX. I won't use a Fram on anything I own.

Down2TheC · **Posted:** 31 Oct 2019 11:29

Great info on my misplaced Fram usage. Thanks.

Meanwhile after digging, it's all in the ZDP. API SN rating was a result of post-2010 auto needs. Zinc and phosphorus in ZDP (ZDDP) makes a glass like coating on the high pressure points of your old school flat tappet diesel (Westerbeke calls ours "bucket" tappet, but it's not a roller) That coating prevent wear for the high pressures of a diesel but ZDP trashes catalytic converters that the auto manufactures had to warranty out to 120k by gov't mandate. So SN was a rating for the car makers.

Lots of tips and opinions out there but Maineiac got it right. When the API was changed they all ran to meet it. Shell moved their Penzoil products to SN to keep the big market, while letting Rotella keep the ZDP and lose the SN rating.

We're in the same boat as truck fleet operators, generators, muscle cars and racing engines. Looking in their forums, our options are to get Rotella or a similar old school oil with the CF rating, or use a ZDP additive.

Only downside of ZDP would be that it reacts with glycol so if you have coolant in your oil, it will make stuff that will end up in your filter.

For this year, I'm using the Penzoil with some Rizlone Zinc treatment ($5 from Amazon)... only because I have the oil already. Next year I'll switch to Rotella T1 for the duration.

But if you've been running API SN for the past five years without noticing the change, the only risk is increased wear on your cams and lifters. Not a big deal for the low usage situation I have (<30 hrs a season) but I'd perk up my ears if I were a long haul cruiser.

Down2TheC · **Posted:** 31 Oct 2019 11:34

cseltzjr wrote:

... and the Fram $6.00 oil filter (again, I forget the number)

PH8A. But that info is obsolete for me now with the above Fram chat. Going to have to remember a new one.

Down2TheC · **Posted:** 31 Oct 2019 11:42

Maineiac wrote:

Rotella. Only and always in all 30W applications. As to FRAM, I suggest watching a few youtube videos. The FRAM filters are pure garbage, and there's one on my W50 right now. WIX is the way to go. There's actually a filtration system in the WIX filters whereas the Fram filters are paper dolls. Literally.

https://youtu.be/fx_4oN54qlU
Skip to 6:30

And here I just liked the textured grip on the end of the FRAM.

cseltzjr · **Joined:** 16 May 2009 08:06 **Posts:** 254

I guess I don’t know what to say about this. I watched the video and it is clear that the filter that has been protecting my engine(s) for all these years is substandard in design and manufacture. I wonder how much of the over / under design / build is designed to protect (continue some oiling) after the filter is clogged. I don’t know. The paper element in the Fram filter removes particles down to a certain size as do all the others. If the filter is changed before (in my case well before) it becomes overwhelmed, is the rest really meaningful? I guess the same goes, to a degree, on the oil itself. My oil turns pretty black (evident on the dipstick) within a couple hours running time after every oil change and it always has. I have been pretty diligent about using the same oil and filter (brand) for nearly 40 years over 2 boats. I believe regular maintenance is the most important component in the process.

$.02

Maineiac · **Posted:** 01 Nov 2019 10:38

Exactly. I tore apart filters years ago and made the Fram determination, then someone pointed out the youtube videos.

Maintenance, oil changes and good lubrication. These are sailboats, not motorboats, so, hopefully, the engines are over-maintained if anything. The only point was that if you want to guarantee proper filtration, lubrication and expected filter life, go with the good stuff. I always used to think Fram was top of the line until I tore one apart. Then youtube confirmed my suspicions. I look at any engine with a Fram filter on it with trepidation. Got one right now in my boat.

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W50 oil ratings. What's in your diesel?

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