engine oil - modern equivalent of CD standard

SAWDOC

SAWDOC

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hi all
My Volvo Penta MD11c technical data sheet specifies an engine oil of diesel oil quality CD. Viscosity is stated as SAE 20 (over 10 degrees) and SAE 10w below 10 degrees.
This grade of oil does not seem readily available.
Can anyone advise if there is an equivalent oil currently available in the likes of Halfords?

thanks
 
The current equivalent is CF spec. Halfords sell an oil to this spec 15w/40 labeled for "older diesel engines".

if you want to stick to single grade oil I think Morris Oil still sell it.
 
Speak to morris oils. I bit the bullet and had a 25ltr can of their oil delivered for my Yanmar engine.

Been previous discussions on this and it's important not to use either synthetic or higher grade oils.

Counter intuitive I know not to use the best latest oil available.
 
I noticed asda were doing 4 litre of Castrol GTX 15/40 Marked as CF but on the front it says Synthetic Technology. At £16 for 4 litres I didn't think it could be synthetic oil. Anyone have any ideas if it's suitable for a Yanmar 2GM20?
 
Spyro said:
I noticed asda were doing 4 litre of Castrol GTX 15/40 Marked as CF but on the front it says Synthetic Technology. At £16 for 4 litres I didn't think it could be synthetic oil. Anyone have any ideas if it's suitable for a Yanmar 2GM20?
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Castrol's Synthetic Technology oil is a Group 3 that they claim has the properties of a Group 4 synthetic. There is a useful page on it in wiki https://en.wikipedia.org/wiki/Synthetic_oil. I use their 10w-40 version in my kit car, where it seems to perform well, but that tends to run very hot at times. Not sure it's the best to use in a raw-water cooled engine but probably satisfactory.
 
Comma do a basic 15:40 mineral oil. i get it from my local Motor Factors. They also do a classic oil 20:50 but it's more expensive and aimed at petrol engines (I use it in the Morris 1000).
 
Sailfree said:
Speak to morris oils. I bit the bullet and had a 25ltr can of their oil delivered for my Yanmar engine.

Been previous discussions on this and it's important not to use either synthetic or higher grade oils. Counter intuitive I know not to use the best latest oil available.
Click to expand...

Higher grade oils cope with higher temperatures. This may be unnecessary but I fail to see how this would harm an older engine. Modern oils hardly contain chemicals likely to dissolve cast iron or phosphor bronze be it elderly or new.

I just buy "oil for elderly diesel" for my 36yr old Bukh. The SAE range is better on some oils so if thinner when cold it will start better and thicker when hot it will cope with worn bearings and cylinder better so SAE10-40 is better for old and worn than SAE 20-30.

For the rest I fear a con, like the soap medicine and soap makers putting exactly the same ingredients in a great range of products.
 
oldmanofthehills said:
For the rest I fear a con, like the soap medicine and soap makers putting exactly the same ingredients in a great range of products.
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Hardly a con. The point is not that sophisticated oils might do harm but that they are a waste. They are designed for engines that are totally different from our simple low powered engines. You don't need to go into the technicalities but logic says that an automotive engine that produces 2 or 3 times the power for size of engine, runs at 50% higher revs and has to cope with a duty cycle that includes high load cold starts, periods at idle, rapid acceleration and long high load runs needs a different type of oil than a yacht auxiliary that runs most of its life at half power at constant revs and temperature.
 
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