Which oil M103 engine.

[Deadly Dave]

I have always used mineral oil in my 1988, 300CE. She has 123k miles on the clock. Is mineral still the best suited or should I use semi or fully synthetic ?
Thanks, Dave.

 

[grober]

I would advise a good 10W40 semisynthetic changed with its filter at around 6,000 miles. 2 examples
Shell Helix HX7 10W-40 synthetic technology engine oil
Fuchs TITAN SYN MC 10w-40 Semi-Syn Engine Oil (XTR)

 

[190]

I think a quality semi synthetic would have been recommended back in 1988 when the car was new but it's no big deal that you have used mineral oil. The main benefit you would get from a modern synthetic is a 0W40 or 5W40 would be thinner when cold. If the car sleeps outside in the winter I would use a 0w40 or 5W40 but if inside or not used much in the winter then 10W40 would be fine.

There are some good reason to use synthetic oil but big differences in engine wear is not one of them.

 

[Deadly Dave]

She only does about 1K miles of summer driving per year but sleeps outside.

 

[Deadly Dave]

I think a quality semi synthetic would have been recommended back in 1988 when the car was new but it's no big deal that you have used mineral oil.

The handbook doesn't specify mineral or synthetic .

 

[190]

I can't remember what the manual said because it's a long time ago, but when I had my 1989 190e serviced they always used a semi synthetic oil. Does the handbook say anything about an MB's oil spec. 229.3 would be the likely one. If you use an oil approved to MB 229.3 you can't go wrong. There are later and better specs but for 1000 miles per year they are not necessary. If you haven't or don't want to use an MB approved oil then the absolute minimum spec I would look for in an oil is ACEA A3/B4. MB 229.3 is really only A3/B4 with a few minor tweaks.

 

[Deadly Dave]

Thanks. I will recheck the manual and report back .

 

[Gazwould]

I would advise a good 10W40 semisynthetic changed with its filter at around 6,000 miles. 2 examples
Shell Helix HX7 10W-40 synthetic technology engine oil
Fuchs TITAN SYN MC 10w-40 Semi-Syn Engine Oil (XTR)

+1

 

[Gazwould]

No real reason why you couldn't use a fully synthetic 5W40 though .

 

[Deadly Dave]

The manual says 226.0, 226.1, 227.0, 227.1.

 

[markjay]

Try here:

Mercedes-Benz Specifications for Operating Fluids: Overview Sheets

 

[grober]

posted by mistake

 

[markjay]

In the nineties they used to say that it's not a good idea for older engines to run on synthetic oils.

The issue was (supposedly) that the seals used in older engines were not compatible with the chemical make-up of the new synthetic oils, resulting in oil leaks.

The advice at the time was to stick with mineral oil for older cars.

No idea if this is still applicable though....

 

[markjay]

Guess not... see Myth #3:

Five Common Myths About Engine Oil

 

[markjay]

EDIT

 

[190]

The manual says 226.0, 226.1, 227.0, 227.1.

Those are old specs are no longer listed by MB but it's interesting to note that the nearest old spec 226.5 shows predominantly 5W40 oils. 5W40 is inherently not a straight mineral oil because the viscosity range is too wide. It's typically a group 3 oil and usually at least "semi synthetic".

I wouldn't have the slightest concern about running an older car on semi or "full synthetic" and used both in my 1989 190e without any problems.

Now we've all been using the term synthetic without qualification and although this is perhaps not the thread to go off on a tangent, there one reason not to be concerned about Synthetic oils affecting seals and that's because that the vast majority of them are not actually synthetic in the true sense at least not unless you are pay £40 or £50 for 5 litres.

Keeping it simple, I'd just use a branded quality oil of any flavour, ideally meeting 229.3 but as a minimum look for ACEA A3/B4. You will then be using something of better quality that what was available when the car was built.

 

[Deadly Dave]

In the nineties they used to say that it's not a good idea for older engines to run on synthetic oils.
/QUOTE]
That was my concern

Guess not... see Myth #3:

Five Common Myths About Engine Oil

No longer concerned

Thanks all for the advice.

 

[190]

In the nineties many oils that were marketed as synthetic actually were still synthetic e.g. Mobil 1 Now almost non of them are synthetic including Mobil 1. It's not anything for anyone to worry about and it's only worth mentioning to allay fears about using synthetic oil in older cars.

Buy oil on the performance specification and not what the marketing departments call it.

 

[Gazwould]

Oil performance perameters via manufacturer spec and not irrelevant ancient handbooks.

 

[optimusprime]

I have had cars for over 50 years and i have never seen any oil other than mineral oil back then in 1989 era