Yanmar 2GM20 Oil

[Tranona]

"Rigorous scientific analysis" ..... are you being serious Tranona? This forum, and all other forums, is about experience and opinion.

If you want "rigorous scientific analysis" you can try the oil manufacturer or the engine manufacturer. The oil manufacturer will say "We don't know, ask the engine manufacturer" and the engine manufacturer will say "We haven't tested our engine with the type of oil you are suggesting". Both of these responses mean that synthetic oil might be really bad or might be really good or might make no difference ..... which is where experience and opinion comes into it.

Richard

This gets to the heart of the issue. It is your "experience and opinion" that I am questioning when set against the "rigorous scientific analysis" used by the experts at the oil companies and engine manufacturers.

What you claim the oil companies are saying is simply not true - read the statements again. Each give reasons why synthetics are not needed and may be harmful. Similarly the manufacturers state quite clearly they are not necessary. Do you seriously suggest that they have not carried out extensive tests on their engines with different oils before making their recommendations?

Your experience does not tell us that small low powered marine diesels will not be harmed, nor that there is any benefit using synthetic oils. All you say is that your car engines are clean inside and don't show wear after running for about half their design life. It would be much more convincing if you ran one of your Yanmars on synthetic and one on mineral for 3-4000 hours then stripped them down and compared wear (and cleanliness if you must). Records of usage cycle oil and fuel consumption over the period would also help.

In the meantime all we have is your opinion based on largely unrelated experience. Not really enough to trump the oil company experts.

 

[VicS]

Who'd have thought such a simple question could elicit such complicated answers. Talk about bore glazing - my eyes were glazing! BTW what's the DS that was referred to?
I use mineral to API CD 5-40.

Citroën DS ? JD's car!

 

[richardabeattie]

Bet the OP is now in hiding under an assumed name!

 

[vyv_cox]

I use mineral to API CD 5-40.

5? Should that read 15w?

 

[RichardS]

Bet the OP is now in hiding under an assumed name!

Never mind the OP ...,, I'm going under an assumed name 'cos I'm wasting my time under this one.

I had exactly these same discussion back in the 1970's, although not on the internet because it wasn't invented, when the first synthetic oil, Mobil 1, was released in the UK.

I spoke to Vauxhall and Yamaha about whether I should use it in my engines and both said "We've not tested it with our engines so our recommendation is categorically not to use it". Of course, I totally ignored their recommendations and look where we are now. :encouragement:

Just give it time boys and everything will come around to my way of engineering.

Richard

 

[MonniotC]

Please correct me if I'm wrong, but I was under the impression that the argument against using synthetic oils in old engines was as follows:

You have an old engine that's been run for years/decades on low spec oil, quite possibly with infrequent oil and filter changes. Although it runs perfectly, there is lots of accumulated grunge hiding inside the engine in all the nooks and crannies. Then you switch to synthetic oil, which has much more detergent in it. This has the effect of loosening all the accumulated grunge. The danger is that a largish bit of loosened grunge blocks a critical oilway and causes catastrophic failure/seizure.

I'm pretty sure that that's the argument which is used against switching to synthetic. I have no idea what the actual likelihood is of that happening, or even if there are any recorded examples. The argument would be irrelevant, of course if you were using synthetic from new.

 

[ghostlymoron]

5? Should that read 15w?

Yes you're correct Vyv (as usual)

 

[lw395]

Please correct me if I'm wrong, but I was under the impression that the argument against using synthetic oils in old engines was as follows:

You have an old engine that's been run for years/decades on low spec oil, quite possibly with infrequent oil and filter changes. Although it runs perfectly, there is lots of accumulated grunge hiding inside the engine in all the nooks and crannies. Then you switch to synthetic oil, which has much more detergent in it. This has the effect of loosening all the accumulated grunge. The danger is that a largish bit of loosened grunge blocks a critical oilway and causes catastrophic failure/seizure.

I'm pretty sure that that's the argument which is used against switching to synthetic. I have no idea what the actual likelihood is of that happening, or even if there are any recorded examples. The argument would be irrelevant, of course if you were using synthetic from new.

Not exactly.
The amount of detergent in an oil is a separate issue from whether it's synthetic or not.
What you are saying is very relevant if you have an old engine which has been run on non-detergent oil.
There is a confusion in some circles between 'straight' oil meaning non-detergent or meaning monograde.
In the classic vehicle industry, there are retailers of non-detergent oils, monograde oils and all combinations.

I think it's partly true that higher spec oils have more detergent, but not necessarily so. AIUI, motorbike oils tend to have less detergent, because they are normally changed more frequently. OTOH, when I bought my latest car, the first oil change I did myself, I switched it to the correct manufacturer-specific synthetic oil, which seemed to get dirty quite quickly. Subsequent changes have gone a good distance and still come out looking more reasonable.

So in my view, it's good to stick to known brands of oil, so you don't randomly switch between detergent and non-detergent and other additives.
Changing to a better oil in detergent quantity/quality terms can have positive effects like freeing up piston rings, reducing oil consumption.

 

[Motor_Sailor]

When I had a 2GM20, I thought it took SAE 30 in engine and gearbox.

Millar oils still do a monograde at £25 a gallon.

 

[RichardS]

When I had a 2GM20, I thought it took SAE 30 in engine and gearbox.

Millar oils still do a monograde at £25 a gallon.

Arrrggghhhh .... please don't say that. You'll only encourage those who are still living in the past.

Richard

 

[VicS]

When I had a 2GM20, I thought it took SAE 30 in engine and gearbox.

Millar oils still do a monograde at £25 a gallon.

API CC spec too. Just the ticket Also do a multigrade one

 

[vyv_cox]

API CC spec too. Just the ticket Also do a multigrade one

There is a big market for API CC, very many canal boats use it, e.g. for BMC and Isuzu engines. Isuzu say that API CD can be used if CC not available! I buy CC from Morris lubricants for my BMC 2.2 diesel.

 

[SteveIOW]

Intended to do an oil change on my 1993 Yanmar 2GM20 today but having scanned though the 10 pages of this thread I am now totally confused and glad I've put it off to next week.

For many years I have used Halfords 15W/40 "Mineral Diesel Oil" which is described on the label as being suitable "for most non-turbo diesel engines" and "for cars built between mid 1980s and early 1990s". I have had no engine problems and oil usage has been almost zero. Went to get some more this year but couldn't find it on shelf and Halford's assistant advised me they don't sell it any more.

Went to a trade (and private) car spares outlet and they said they could supply the Mineral Oil I needed and I purchased 5 litres of "Pro+Power Gold 15W/40". The label doesn't actually say it is Mineral Oil but does say "A multi fleet motor oil designed for use in both turbo and non-turbo charged petrol and diesel engines. Recommended for applications requiring ACEA AC/B4, API SN/CH-4, MB228.1,MB229.1, VW501.01, 505.00, PSA B71 2295, MAN270/271, Volvo VDS-2"
This is all double Dutch to me. My question is: Is this oil a Mineral Oil and does it meet with Yanmar original recommendation? Am tempted go to Yanmar and buy their oil at their silly prices.

I don't want to be changing to an oil with detergent resulting in increased oil usage and god knows what else.

 

[VicS]

Intended to do an oil change on my 1993 Yanmar 2GM20 today but having scanned though the 10 pages of this thread I am now totally confused and glad I've put it off to next week.

For many years I have used Halfords 15W/40 "Mineral Diesel Oil" which is described on the label as being suitable "for most non-turbo diesel engines" and "for cars built between mid 1980s and early 1990s". I have had no engine problems and oil usage has been almost zero. Went to get some more this year but couldn't find it on shelf and Halford's assistant advised me they don't sell it any more.

Went to a trade (and private) car spares outlet and they said they could supply the Mineral Oil I needed and I purchased 5 litres of "Pro+Power Gold 15W/40". The label doesn't actually say it is Mineral Oil but does say "A multi fleet motor oil designed for use in both turbo and non-turbo charged petrol and diesel engines. Recommended for applications requiring ACEA AC/B4, API SN/CH-4, MB228.1,MB229.1, VW501.01, 505.00, PSA B71 2295, MAN270/271, Volvo VDS-2"
This is all double Dutch to me. My question is: Is this oil a Mineral Oil and does it meet with Yanmar original recommendation? Am tempted go to Yanmar and buy their oil at their silly prices.

I don't want to be changing to an oil with detergent resulting in increased oil usage and god knows what else.

According to ther website Halfords do an own brand 15W-40 mineral diesel and petrol engine oil to API CF-4

Also a Mobil one to API CF


The oil you have bought is API CH-4. I think you will find that Yanmar specifically say do not use API CG-4 or CH-4

 

[Steve_N]

Some pages back in this thread I gave the OP a link to a suitable Mannol oil which I think he bought.
Just for information, they produce 5 different mineral 15w40s (plus a couple of synthetic ones for those of that bent!) as follows.

Mineral 15w40s
MANNOL Diesel 15W-40 API CG-4/CF-4/CF/SL ACEA E3/B3/A3
MANNOL Standard 15W-40 API SL/CF
MANNOL Universal 15W-40 API SG/CD
MANNOL TS-1 15W-40 API CH-4/CG-4/CF-4/SL ACEA E3/A3/B3/B4
MANNOL TS-4 15W-40 API CI-4/CH-4/CG-4/CF-4/CF/SL ACEA E7/A3/B4

Just a satisfied customer - most available at keen prices on Ebay. I've been using their FS 5w30s in our road vehicles too, all three of which require a different spec. and they produce many, many different versions in that grade too. Of course I'm no expert - it could all be coming out of the same barrel..

 

[VicS]

Some pages back in this thread I gave the OP a link to a suitable Mannol oil which I think he bought.
Just for information, they produce 5 different mineral 15w40s (plus a couple of synthetic ones for those of that bent!) as follows.

Mineral 15w40s
MANNOL Diesel 15W-40 API CG-4/CF-4/CF/SL ACEA E3/B3/A3
MANNOL Standard 15W-40 API SL/CF
MANNOL Universal 15W-40 API SG/CD
MANNOL TS-1 15W-40 API CH-4/CG-4/CF-4/SL ACEA E3/A3/B3/B4
MANNOL TS-4 15W-40 API CI-4/CH-4/CG-4/CF-4/CF/SL ACEA E7/A3/B4

Just a satisfied customer - most available at keen prices on Ebay. I've been using their FS 5w30s in our road vehicles too, all three of which require a different spec. and they produce many, many different versions in that grade too. Of course I'm no expert - it could all be coming out of the same barrel..

One of the Yanmar manuals I was looking at a couple of days ago specifically said do not use CG-4 or CH-4 oils

 

[Steve_N]

One of the Yanmar manuals I was looking at a couple of days ago specifically said do not use CG-4 or CH-4 oils

Just general availablity information, Vic, not a recommendation specifically related to Yanmars. 10 pages in the discussion seems to have have broadened somewhat.

 

[VicS]

Just general availablity information, Vic, not a recommendation specifically related to Yanmars. 10 pages in the discussion seems to have have broadened somewhat.

It makes reading long threads like this one a lot easier if you increase the number of posts displayed per page . At 50 pe rpage I am only just coming up to the end of page 2 !

 

[vyv_cox]

One of the Yanmar manuals I was looking at a couple of days ago specifically said do not use CG-4 or CH-4 oils

I find these multiple specification oils very confusing. I like the spec of API CI-4 but have not found one that does not include CG-4 and CH-4, which I am reluctant to use.

 

[lw395]

I find these multiple specification oils very confusing. I like the spec of API CI-4 but have not found one that does not include CG-4 and CH-4, which I am reluctant to use.

This just means it meets the requirements of all three specifications.
By default, it will meet most of the lower specifications too.