Puzzlement over Yanmar engine oil

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Plevier

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Looking at getting a boat with a Yanmar 3YM30 engine and had a look at the manual (2009 edition on their website http://www.yanmarmarine.com/theme/y...e-engines/Operation-manuals/YM_V2_21JAN09.pdf).

Very puzzled by the oil spec.
It says:

Use an engine oil that meets or exceeds
the following guidelines and classifications:
• API Service Categories: CD or higher
TBN value: 9 or more
The oil must be changed when the Total
Base Number (TBN) has been reduced
to 2.0.
• NEVER use API Service Category CG-4
or CH-4 oils.



This seems very contradictory.
Vyv's page http://coxengineering.sharepoint.com/Pages/Oilforyachtengines.aspx says TBN of CD is 4, nowhere near 9.
What is so wrong with CG-4 and CH-4?

As CD is hard to find, it just seems to leave CF and CF-4.

It doesn't mention CI-4 that Vyv's page says Yanmar recommends at all!
 
Troubadour said:
Looking at getting a boat with a Yanmar 3YM30 engine and had a look at the manual (2009 edition on their website http://www.yanmarmarine.com/theme/y...e-engines/Operation-manuals/YM_V2_21JAN09.pdf).

Very puzzled by the oil spec.
It says:

Use an engine oil that meets or exceeds
the following guidelines and classifications:
• API Service Categories: CD or higher
TBN value: 9 or more
The oil must be changed when the Total
Base Number (TBN) has been reduced
to 2.0.
• NEVER use API Service Category CG-4
or CH-4 oils.



This seems very contradictory.
Vyv's page http://coxengineering.sharepoint.com/Pages/Oilforyachtengines.aspx says TBN of CD is 4, nowhere near 9.
What is so wrong with CG-4 and CH-4?

As CD is hard to find, it just seems to leave CF and CF-4.

It doesn't mention CI-4 that Vyv's page says Yanmar recommends at all!
Click to expand...


A clue is in CD or higher
CF 4 is fine, try a local factor or SM for best prices
 
Puzzling indeed! It reads to me that Yanmar believe their engines to be very sensitive to low TBNs. However, it appears that there has been a cockup somewhere, explained by Yanmar http://www.yanmarmarine.com/Confusi...essionid=84303adc1c3ce10696325178272b35975377

API CG-4 and CH-4 have been developed specifically for low sulphur fuels, but then so has CI-4. Yanmar's own oil is CI-4, as it says in their apology. http://www.ebay.co.uk/itm/YANMAR-MA...94221804?_trksid=p2054897.l4275#ht_1949wt_721

Answering RAI, labs routinely measure TBN and TAN to determine the remaining life of the oil. The oil progressively becomes more acidic during its life, particularly when burning fuel with higher sulphur levels. High TAN = low TBN damages certain parts of engines, particularly copper-lead bearings.
 
RAI said:
Thanks Vyv, So I can't test it myself to see if the oil needs changing?
Click to expand...

The reality is that for the average yacht auxiliary engine the temperature and hours run never approach the levels required for significant loss of TBN. Changing oil once per year, as most of us do, will always be sufficient for our engines. Unfortunately it seems that Yanmar are following the same route of 'one size fits all' as Volvo, in specifying the same oil for a single cylinder 10 HP engine as for a turbo-charged, high powered mobo running flat out for hours. Higher TBN is desirable in the latter but considerably less so in the former.
 
vyv_cox said:
Puzzling indeed! It reads to me that Yanmar believe their engines to be very sensitive to low TBNs. However, it appears that there has been a cockup somewhere, explained by Yanmar http://www.yanmarmarine.com/Confusi...essionid=84303adc1c3ce10696325178272b35975377
Click to expand...

The confusion apology is fairly confusing too!
CG-4 and CH-4 are higher than CD.
Hard to see why they have to be avoided and jump straight to CI-4 - which by well rehearsed arguments on here should not be very good for the engine - if (when) CF-4 disappears.
I gather from Googling that CI-4 is TBN 10-11, CG-4 is around 9 or 10 and CH-4 is around 10.
The odd one out seems to be the CD!
 
Troubadour said:
The confusion apology is fairly confusing too!
CG-4 and CH-4 are higher than CD.
Hard to see why they have to be avoided and jump straight to CI-4 - which by well rehearsed arguments on here should not be very good for the engine - if (when) CF-4 disappears.
I gather from Googling that CI-4 is TBN 10-11, CG-4 is around 9 or 10 and CH-4 is around 10.
The odd one out seems to be the CD!
Click to expand...
Check-out the API specs its all there
 
vyv_cox said:
Perhaps you can point me to the API spec for auxiliary yacht engines? The crux of the problem is that the specs are totally automotive based, and still catering for some high sulphur fuels for off-road vehicles.
Click to expand...
All newer spec`s inc all those it supersedes, if the old spec isnt produced you cant have it. unless one finds say, Morris Oils
 
sailorman said:
All newer spec`s inc all those it supersedes, if the old spec isnt produced you cant have it. unless one finds say, Morris Oils
Click to expand...

Unfortunately that is totally not the case. API CD has been available in Uk until very recently, despite having been declared obsolete nearly 50 years ago. It is still available in Europe - I bought some in Italy this year. API CF and CF-4 are available almost everywhere, despite having been superseded by many other grades. In the case of the Yanmar info above, CG and CH are available everywhere despite CI-4 having been developed to replace them. In oils it is horses for courses, many older engines require specific grades, which is why the manufacturers still make them. Morris, who you quote, make API CC and sell a lot of it. It was superseded by CD!
 
vyv_cox said:
Unfortunately that is totally not the case. API CD has been available in Uk until very recently, despite having been declared obsolete nearly 50 years ago. It is still available in Europe - I bought some in Italy this year. API CF and CF-4 are available almost everywhere, despite having been superseded by many other grades. In the case of the Yanmar info above, CG and CH are available everywhere despite CI-4 having been developed to replace them. In oils it is horses for courses, many older engines require specific grades, which is why the manufacturers still make them. Morris, who you quote, make API CC and sell a lot of it. It was superseded by CD!
Click to expand...
Not everybody is able to buy oil in Italy. Just what is available locally
 
I remember a thread a while back when this was discussed so I wrote to Beta about the oil and they came back and said as long as it was mineral oil (not semi or fully synthetic) then the modern grades were okay rather than try to find oils conforming to old obsolete standards. There had been the same debate about the unsuitability of the newer grades - along the lines of Vyv's views - the Beta manual reads API Classification CF (CD or CE) - but then the manual goes on to say 'A good quality SAE 15W/40 mineral based multigrade oil as used in most car diesel engines' and Beta confirmed that mineral oil 15W/40 was all that was needed and not to bother about the newer specs being over rated for the engine.
 
Hello everyone, I write from Italy and I follow you for a long time, I also have one Yanmar 3YM20 and there are important news so I decided to take this thread: I download the new manual for engines Yanmar 3YM20, 3YM30 and the new 3ym30AE (again), they removed the words "use oil with tbn than 9" and have included "use oil with Api CD, CF, CF-4, CI-4 and CI".
I was going to go in there even CI-4 oil, but since they have now removed the word that created confusion (use more than 9) oil with tbn, now continue to use oil Mannol Universal Api CD 15w40 (TBN 5.4) to purchasing from Germany
https://www.oel-guenstig.de/Motoroe...5W-40-Universal-Motoroel-API-SG-CD::1632.html
 
Last edited:
frankcilo said:
Hello everyone, I write from Italy and I follow you for a long time, I also have one Yanmar 3YM20 and there are important news so I decided to take this thread: I download the new manual for engines Yanmar 3YM20, 3YM30 and the new 3ym30AE (again), they removed the words "use oil with tbn than 9" and have included "use oil with Api CD, CF, CF-4, CI-4 and CI".
I was going to go in there even CI-4 oil, but since they have now removed the word that created confusion (use more than 9) oil with tbn, now continue to use oil Mannol Universal Api CD 15w40 (TBN 5.4) to purchasing from Germany
https://www.oel-guenstig.de/Motoroe...5W-40-Universal-Motoroel-API-SG-CD::1632.html
Click to expand...

I use a standard 15W-40 semi-synthetic in my 3YM30s which is rated API CF so that still looks like a good choice for a "synthetic" adherent like me. :)

Richard
 
Morris Oils is situated a stone's throw from where I live. They manufacture/blend their own lubricants and sell a lot to classic car buffs, canal boaters and the like as well as marine boaters. Unfortunately, they only sell in large quantities from their depot but most local car accessory shops (except Halfords) either stock it or will order it in. I've got a gallon of mineral 15-40 from when I had a Yanmar but now only have outboards.
 
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