An answer to the 'what oil for my engine' question

vyv_cox

vyv_cox

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An answer to the \'what oil for my engine\' question

Many of us face the problem that our engines (Yanmar, Bukh, Volvo) need a lubricant that has been obsolete for 10 years. I refer to the specified API CD classification, a query that comes up here very frequently. This oil is not readily available from major manufacturers but can usually be found in car parts shops.

Following a bit of internet research, I contacted Shell's Lubricants Helpdesk. Shell still make a lubricant to API CD, named Rimula C. The full list of Shell's products by country is shown here / Enter the United Kingdom as country and then Rimula in the search box ( best selecting the "all of the above " option )

Rimula C grades are available in the UK, product data sheets and MSDSs available on the website. To find an outlet for the product, contact Shell UK directly on 0870 8500924

I confess a small conflict of interests here, as I retired from Shell a few years ago. Just to balance things out a little, I tried searching several other oil companies' websites. I cannot find any oils to API CD by Exxon-Mobil but I did find Total Rubia H and Rubia B, to API CD and CC.
 
Re: An answer to the \'what oil for my engine\' question

I have found that chandlers servicing canal craft seem to stock a wide range of oil for older engines.

Notwithstanding this older specification oils were all "mineral" and not synthetic or semi synthetic. I had also understood that "CD" stood for Compression- grade D and therefore anything Mineral with " C " followed by "D" or a later alphabetic letter was satisfactory.
Generally this means the cheapest diesel oli vaialbale in car parts shops or the supermarket - target price no more than £11 for 5 litres.

Regards
 
Re: An answer to the \'what oil for my engine\' question

Be very careful using fancy oil in old engines.
With all the new chemicals designed to "clean" the oilways and protect the engine years of crud that sat harmlessly in your engine will be dislodged and make a 'orrible blockage,

I speak from experience with an old volvo, I did an oil change, new filters super new fandango "Best" oil then in half an hour there was a horrible squeaking noise from the top of the engine then it siezed. The crud had been dislodged and blocked the oilway to the head.

The mechanic said - yep see this all the time, old engines need plain old oil fella, cheap as yer like but change it more often.
 
Re: An answer to the \'what oil for my engine\' question

<<< followed by "D" or a later alphabetic letter was satisfactory >>>

Definitely not. There has been a thread on the subject in the past two weeks. Using oils to higher alpabetic grades, e.g. CG, CI, etc will harm a low-power, normally aspirated engine. Even CF-4, declared to be a direct replacement for CD by several oil companies, including Castrol, causes a number of documented problems when used in yacht auxiliary engines.
 
Re: An answer to the \'what oil for my engine\' question

Now you've got me worried. I usually use plain old Halfords diesel engine oil but at the end of last season my local Halfords didn't have any. Cheapest was Halfords brand 'semi-synthetic' so I bought 5L of that. There was some big brand ‘basic’ diesel engine oil but for some reason Shell etc have started selling it in 4L containers rather than 5L. My MD22L needs nearer 5L with a filter change so I plumbed for the Halfords semi-synthetic. The boat’s been ashore since but is due back in the water early March. Can I rest assured it'll do the job or do I need to do a cautionary oil change before I run the engine in anger?
 
Re: An answer to the \'what oil for my engine\' question

I cannot believe that 100 hours or so of using a semi-synthetic will cause any major problems. Do you know what API classification it is made to? If it's a CF-4 I wouldn't worry until next scheduled oil change, when I would definitely go for a CD. If it's higher than that, maybe CG or CI, I would change it mid-season or at about 50 hours.

The consequence of using higher grades in low performance engines is more wear, of bores and cams, especially at prolonged tickover, e.g. battery charging. However, it is not going to wipe these components out in 100 hours or less.
 
Re: An answer to the \'what oil for my engine\' question

So.
If I buy, from my local car bits shop, a cheap mineral oil specifically intended for non-high-performance diesel engines and marketed by a respected name, and change said oil every 6 months, am I OK or heading for mechanical disaster?

A possible alternative for Yanmar owners is to buy Yanmar oil which would appear ideal on all counts except price. Does this do anything which a cheap mineral oil from Halfords won't?

and finally - a slightly related topic - changing the oil filter is, for a small (1GM) engine like mine, probably more expensive than changing the oil! Presumably, unlike oil which deteriorates (when in an engine) over time, a filter will carry on filtering until bunged up with assorted crud. So can I leave the same filter in until it has seen the x hours recommended by the manufacturer, which might mean leaving the same filter in for two or three years? or should I change it every year even if the engine has done few hours?
 
Re: An answer to the \'what oil for my engine\' question

[ QUOTE ]

The consequence of using higher grades in low performance engines is more wear, of bores and cams, especially at prolonged tickover, e.g. battery charging. However, it is not going to wipe these components out in 100 hours or less.

[/ QUOTE ]

I accept the collective wisdom of what you say but would like to understand it more. ie Why?

I though synthetic oils had more long chain molecules etc and caused less internal friction losses in the engine such that on some engines the effect of changing to a fully synthetic caused an increase in tickover speed.

Is it that the greater tolerances/gaps in a "cooking" low tech engine place higher loads on a synthetic oil that it can't cope with?

Can anyone explain it in a simple way?
 
Re: An answer to the \'what oil for my engine\' question

Vyv - What about the Turbo diesels - VP 2003T - I think I use a basic oil in that - must check up. But does CD also do for that?
 
Re: An answer to the \'what oil for my engine\' question

First question - that's what I do. Additive packages for an API CD lubricant are very well established now, so the cheap oil manufacturer will buy his base oil from his nearest refinery and add a package from a recognised supplier that will work pretty well.

<<<< A possible alternative for Yanmar owners is to buy Yanmar oil which would appear ideal on all counts except price. Does this do anything which a cheap mineral oil from Halfords won't? >>>
I would put money on it that Yanmar's oil is bought in from one of the majors who still makes API CD. As I have now found out, Shell is still producing Rimula C so there's a good chance that that is what the Yanmar stuff is. This will probably have a slightly better quality package than the stuff from the car parts shop but it isn't going to make a world of difference.

On filters, I always change mine at the end of the season but if I have done enough engine hours for an oil change mid season I leave the filter alone.
 
Re: An answer to the \'what oil for my engine\' question

Which oil is right for you?
The current and previous API Service Categories are listed below.
Vehicle owners should refer to their owner ’s manuals before
consulting these charts.Oils may have more than one performance
level.
For automotive gasoline engines,the latest engine oil service
category includes the performance properties of each earlier
category.If an automotive owner ’s manual calls for an API SJ
or SL oil,an API SM oil will provide full protection.For diesel
engines,the latest category usually – but not always – includes
the performance properties of an earlier category.
Note:API intentionally omitted “SI ” and “SK ” from the sequence of
categories.For more information about API ’s Engine Oil Program,visit
our website at www.api.org/eolcs.
Copyright 2004 -American Petroleum Institute.All rights reserved.
API,the API logo,the API Service Symbol (Donut),the API Service
Symbol with CI-4 PLUS logo and the API Certification Mark (Starburst)
are either trademarks or registered trademarks of the American
Petroleum Institute in the United States and/or other countries.
Printed in U.S.A.Creative Services |24137 |09.04 |Product No.F1551MO
For all automotive engines currently
in use.Introduced November 30,2004,
SM oils are designed to provide improved
oxidation resistance,improved deposit
protection,better wear protection,and
better low-temperature performance over
the life of the oil.Some SM oils may also
meet the latest ILSAC specification
and/or qualify as Energy Conserving.
For 2004 and older automotive engines.
For 2001 and older automotive engines.
For 1996 and older engines.Valid when
preceded by current C categories.
For 1993 and older engines.
For 1988 and older engines.
CAUTION —Not suitable for use in
gasoline-powered automotive engines
built after 1979.
CAUTION —Not suitable for use in
gasoline-powered automotive engines
built after 1971.Use in more modern
engines may cause unsatisfactory
performance or equipment harm.
CAUTION —Not suitable for use in
gasoline-powered automotive engines
built after 1967.Use in more modern
engines may cause unsatisfactory
performance or equipment harm.
CAUTION —Not suitable for use in
gasoline-powered automotive engines
built after 1963.Use in more modern
engines may cause unsatisfactory
performance or equipment harm.
CAUTION —Contains no additives.Not
suitable for use in gasoline-powered
automotive engines built after 1930.
Use in modern engines may cause
unsatisfactory engine performance
or equipment harm.
Gasoline Engines
Category Status Service
SJ Current
Current
SH Obsolete
SG Obsolete
SF Obsolete
SE Obsolete
SD Obsolete
SC Obsolete
SB Obsolete
SA Obsolete
SM
SL
Current
Diesel Engines
Category Status Service
CI-4 Current
CG-4
CF-4
CF-2
Obsolete
CF
Obsolete
CE Obsolete
CD-II Obsolete
CD
Obsolete CC
Obsolete
Current
Current
Current
Current
CB
CA
Introduced in 2002.For high-speed,four-stroke
engines designed to meet 2004 exhaust
emission standards implemented in 2002.CI-4
oils are formulated to sustain engine durability
where exhaust gas recirculation (EGR)is used
and are intended for use with diesel fuels
ranging in sulfur content up to 0.5%weight.
Can be used in place of CD,CE,CF-4,CG-4,
and CH-4 oils.Some CI-4 oils may also qualify
for the CI-4 PLUS designation.
Introduced in 1998.For high-speed,four-stroke
engines designed to meet 1998 exhaust
emission standards.CH-4 oils are specifically
compounded for use with diesel fuels ranging
in sulfur content up to 0.5%weight.Can be
used in place of CD,CE,CF-4,and CG-4 oils.
Introduced in 1995.For severe duty,high-speed,
four-stroke engines using fuel with less than
0.5%weight sulfur.CG-4 oils are required for
engines meeting 1994 emission standards.
Can be used in place of CD,CE,and CF-4 oils.
Introduced in 1990.For high-speed,four-stroke,
naturally aspirated and turbocharged engines.
Can be used in place of CD and CE oils.
Introduced in 1994.For severe duty,two-stroke-
cycle engines.Can be used in place of CD-II
oils.
Introduced in 1994.For off-road,indirect-
injected and other diesel engines including
those using fuel with over 0.5%weight sulfur.
Can be used in place of CD oils.
Introduced in 1985.For high-speed,four-stroke,
naturally aspirated and turbocharged engines.
Can be used in place of CC and CD oils.
Introduced in 1985.For two-stroke cycle
engines.
Introduced in 1955.For certain naturally
aspirated and turbocharged engines.
CAUTION —Not suitable for use in diesel-powered
engines built after 1990.
CAUTION —Not suitable for use in diesel-powered
engines built after 1961.
CAUTION —Not suitable for use in diesel-powered
engines built after 1959.
MOTOR OIL GUIDE
AMERICAN
PETROLEUM
INSTITUTE
CH-4 Current
 
Re: An answer to the \'what oil for my engine\' question

Vyv,

Just to pick your brains a bit more, what about a brand new engine?

I'm planning on replacing the Volvo with a Beta 38.

Mike
 
Re: An answer to the \'what oil for my engine\' question

There is a far more comprehensive reply further down the forum, so suggest you look there also.

The problem is not the synthetic lubricant itself, it's the additive package that is put in it, and specifically its TBN (total base number). Synthetics were developed for high performance engines to prevent coke and gum deposits. It follows that the additive package that is put in it is also high performance, and this means giving it a TBN of 12 - 15 to combat acidic conditions in this type of engine. The TBN required in a normally aspirated, small, low-power engine such as in a yacht is somewhere around 3-4. Using a high TBN oil in a yacht auxiliary engine will lead to wear.

For a turbocharged yacht engine I suggest you look through the Shell website linked above. There are Rimula grades for every type of engine. Sorry to quote Shell but their information is high quality and they seem to be almost the only manufacturer still making the lower grades. Plus, I have very good contacts there.

As ever, follow the engine manufacturer's advice if at all possible.
 
Re: An answer to the \'what oil for my engine\' question

I know what the API says. It is a fact that the replacement grades cause wear in a whole range of older engines. Search the internet for owners clubs of many older cars, e.g. Morris. They even blend their own oils to overcome the problems. There are many others, perhaps not going quite so far as that, but all referring to observed problems with their engines run on high performance oils. Agricultural engines are another example - they also use low TBN oils for the same reasons.

Ask yourself this - if API CD can simply be replaced by API CF-4, why do Shell and Total, plus maybe others, still make them? And why do Bukh, Yanmar, Volvo, still quote API CD?
 
Re: An answer to the \'what oil for my engine\' question

I don't know the engine but I guess that Beta will advise a lubricant. If it's a normally aspirated unit I would think it might well be an API CD or perhaps a CF-4. I'd be glad to know if you can find out.

Vyv
 
Re: An answer to the \'what oil for my engine\' question

A most interesting and informative thread, thanks for a good read!

Just to add another perspective, one of the main reasons that the engine maker does not recommend a later-upgrade of oil spec is down to commercial considerations. There is risk, however small, in making a recommendation without having tested and validated the change. Putting an otherwise obsolete engine on a dynamometer for several thousand hours is pretty expensive and, as far as the maker is considered, pointless. That's why he still recommends CD and hence why the oil producers still provide it.

I think the concept of dislodging sludge is a bit dodgy, too but I'll refrain from comment (oops, I just did). How about the good practice of using a flushing oil in older engines. Another can of worms, eh?
 
Re: An answer to the \'what oil for my engine\' question

Thanks to vyv_cox for casting some light into this murky area. I used to buy agricultural oil for my old MD7A engine but more recently I have gazed long and hard at the rows of cans on the shelf without much of a clue. At least now I am confused at a higher level!!!
 
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