questions about oil for 6.9

[xwill]

I have recently bought a 6.9 on ebay and I have posted this message because I am looking for some information about the type of oil to use. I replaced the spark plug, leads, distributer cap so I am now looking for info about the tpe of oil to use. I have have searched for information but i was looking for what type was used.
Also will many American parts fit an Australian car because I was going to buy some parts from here including an oil filter -  https://www.autohausaz.com/search/category.aspx?sid=mwiyy345tglncwmlvxafi045&modelid=1367603@450SEL&year=1979&makeid=800016@Mercedes
but i am concerned that because that there could be some differences.

thank you
William

[WGB]

As far as oil goes- my 450(non 6.9) likes plain old Castrol GTX 20W-50. If I use anything newer or slipperier (Even GTX2) it starts to drink a little of it.

It would be  brave man who would try a Synthetic as I would suspect it would lead to leaky seals (The detergents in the synthetics clean things a little too well and are a little too slippery for old seals to keep in) and some extra would slip past the rings.

Having said that - the above was widely reported on a Porsche site of which I was a member - I used Castrol synthetic 10W-60 in my late 944 with no problems.

I don't know if the dry sump necessitates any oil in particular but I would have thought reasonable quality oil of the correct grade and changed regularly.

Bill

[s class]

Bill,

My M110 has been completely rebuilt, and for 5 years since the rebuild I have always used Castrol Futron 10W60 semi-synthetic.  I've always had zero oil consumption.  However, Castrol took Futron off the market 6 months ago, and I've been forced to switch to their Edge Sport 5W60 (I think) which is a fully synthetic.  Now I burn off about half a litre per 1000km. 

to answer Xwill's question, I think it depends a lot on the condition of the engine.  Make sure you use a suitable viscosity though.  I've always found GTX2 good in engines with a highish mileage. 

Ryan

[xwill]

Thank you for the answers
I also have a 450se 4.5 which i use 20w50 castrol gtx which i then added a little shell helix 25w-60.
When I was searching, someone said that castrol magnatech was ok. I will look for 10W60 today. The engine has done about 350000kms and it feels like it is in good condition.

[s class]

xwill,

I think something in the 20W50 range is similar to what was originally recommended by MB.  Be aware that Magnatec is 5W40, and is a thin oil.  At 350 000km I suspect you may have excessive consumption.  Where are you located?  If you are in the northern hemisphere, 5W40 may be a good choice, but in the Australian/South African climate, I'd be looking for a 10W60, 20W50, 20W60 or similar. 

Ryan

[xwill]

Thank you for your advice everyone, I will get some good quality 20W50 or 20W60 tomorrow, I was unsure if I needed a thin oil or not because of the differences between the 4.5 motor. And also I can see that this is a great forum.