Oils Revisited - Low Use 6.9

[Lukas]

Hi all,

Am about to put new oil in the 6.9, and want some suggestions please. The previous oil thread (http://topklasse.org/forums/showthread.php?t=1755) has people suggesting everything from the Valvoline cheapie 20W50 to Penrite HPR50, HPR30, Mobil 1 and WGB's super-pricey Redline.

My specific circumstances are low and infrequent use (max 1,500km/year), usually during ambient temps of between 10 and 35 degrees C, for reasonable length drives, usually outside town. Gentle driving usually, occasionally brisk

Also, what oil change interval in these circumstances? I'v been told no longer than 1 year apart, no matter what - if that is the case, the more expensive oils are less appealing again (because $150 of Mobil 1 every year is a lot of $ compared to $50 of Valvoline XLD).

So, what do you use in your 6.9, how often do you change the oil and how is the car driven?

Ta

Lukas

 

[SEL_69L]

The usage profile for my 6.9, perhaps not surprisingly, is almost identical. My car has covered 26,000 klm in 10 years, and in the last 5 years, about 1500 klm per year.

For a daily driver, I change the oil every 6 months, irrespective of the distance covered. On the other hand I have been told that the oil should be changed every 6 months, no matter what, because the oil starts to acidify even when the engine is used only occasionly.

Like Lukas, I'm all ears for opinion in this thread.

 

[BenzBoy]

Oil is simple.
You change it every 6 months regardless of how little you use it and more regularly if you do hard miles such as frequent cold starts and very short trips or long distances in a dusty environment. That is made clear by M-B in the W116 service handbook.
Of course good synthetic oils such as Mobil 1 and Pentrite Sin are only a fraction more expensive to buy - well, maybe more than a fraction more expensive but the comparison between mineral and full synthetic makes the performance differential worth the while.
Critical is the grade you choose. That depends on the original specifications and the degree of engine wear. On a 30 year old motor something like 20-60 would be appropriate.
Forget about the claim that synthetic makes an older engine leak through the seals. What it will do is remove the gunk that may be helping to seal sumps etc and then the motor will leak but it was plugged with gunk so imagine what your oilways are like!
If I were changing to synthetic I would do a number of regular changes to get the engine clean and then move to the oil of my choice.
Good luck Lukas - only you can decide. We here will probably argue over oil until the electric car takes over...
Regards,
Benz-Boy
Ps. Repco does a lovely line in recycled oils at about $2 a litre suitable for Great Walls and Cherries...

 

[TJ 450]

Lukas,

It's up to you really, but I wouldn't go with a 20W-50. The owners manual suggests a lighter cold start rating is preferable... particularly in your climate.

I'm using Mobil Super 2000 x2 semi synthetic 10W-40 in my 6.9 now. I just pulled the rocker covers last weekend and it's super clean in there. The engine is quiet with no sewing machine noises. I'm going to continue with this oil, and it is what Mercedes dealers will use in the car unless you specify Mobil 1.

When I was using Castrol GTX, there was some heavyweight goo forming around the cam oilers and rocker pivots.

Tim

 

[TJ 450]

BTW going by the book, the 6.9 has an extended oil change interval... one year vs. the normal six months. That's fortunate, because the capacity is about twice that of a 450 etc.

Tim

 

[Michel]

BTW going by the book, the 6.9 has an extended oil change interval... one year vs. the normal six months. That's fortunate, because the capacity is about twice that of a 450 etc.

Tim

Was it 12 litres of oil changed every 20,000kms (or one year, whicher came first)?

 

[John S]

You cannot go wrong in using Mobil 1, 15W50 in any of the older Mercedes. Australia does not get cold enough to warrant using any thinner grade of oil.

 

[Styria]

I once tried to follow the MB oil changing schedule, i.e. at 15 thousand kilometer intervals. It may well be that the oil I drained was perfectly useable, but its appearance was like hot, brown and thin water and I said to myself "never again" and I have followed that resolution.

Nowadays I change oil and filter every six months at the latest, together with a new filter each and every time. The oil I use is Castrol Magnetite - I think, from memory, it is a 10W-40W viscosity, but I must stress that Gleaming Beauty is a daily driver, at about 8K. kilometers per year, under favourable traffic conditions. My preference would, and should always be, Synthetic Oil, but in all honesty the expense of the oil change cannot always be justified - not at 12 liters per oiltank ful. At about 380K. kilometers mileage, oil consumption is negligible, and Gleaming Beauty does not leave a blue oil haze around. Incidentally, many years ago, I used Castrol GTX but found that it would gum up the valve gear. Maybe the stuff is better nowadays, but the Magnatite will do me. Regards Styria

N.B. I should also mention that I drain the oil tank and oil cooler (standard on high compression engines) each and every time, and I also use kerosene to clean out the tank and the small sump as well. It's extra work and time, but that's how I prefer it.

 

[Michel]

N.B. I should also mention that I drain the oil tank and oil cooler (standard on high compression engines) each and every time, and I also use kerosene to clean out the tank and the small sump as well. It's extra work and time, but that's how I prefer it.

Thank you Godfather,

I appreciate the extra service every time..

 

[Styria]

Thank you Godfather,

I appreciate the extra service every time..

Michel, I have taken to doing this only in the last eighteen months or so. Gleaming Beauty was the catalyst in doing the extra cleaning at the time when I carried out the valve grind and de-coke together with Mercules' expertise. By necessity I wanted to start with a clean sheet, having regards to the fact that I had a huge problem with an oil/water mixture caused by a leaking head gasket at the back of the off side (driver's ) head.

I also found on removal of the oil tank drain plug, that gunk and carbon, well gunk anyway, had built up and become solidified to the extent that the oil would not drain out. So a thorough clean was necessary. I now repeat this procedure everytime I change oil and filter. It takes an extra hour, but it is worth it. As a rule, I also degrease the underside of engine and gearbox at the same time - again, a job well worth doing.

At the time of the valve grind and decoke, I had also removed the water pump and the housing located between pump and engine block. This enabled me to flush out all rust scale and sediment from the engine block using pressure from the garden hose and compressed air. The amount of rusty sludge removed was 'impressive', to say the least. Regards Styria

 

[motec 6.9]

Hi guys the oil i used to use in my 6.9 was Mobil 1 but then i used to work for Mobil and it was at the right price with discount the oil i have in my 6.9 with the engine from Goldie2 fitted is Royal Purple after talking to engine builder also recomended Redline as for cost if you have to ask

 

[Styria]

Well Motec 6.9, no need to be coy about the price of Redline - WGB has already given us a run down some while ago - seeing that he is the resident Medico, it is easy to appreciate that he's the only one with pockets deep enough to fish out that oil. Regards Styria

 

[motec 6.9]

Actualy Styria Royal Purple was $4 dearer that Redline a ltr

 

[Styria]

Actualy Styria Royal Purple was $4 dearer that Redline a ltr

...well, who on earth makes Royal Purple ? Do you know anything about AMSOIL SYNTHETIC ? I know just that little bit about it. Regards Styria

 

[motec 6.9]

Hi Styria i chose Royal Puple on the recomendation of my engine builder he also recomended Redline said he has seen as much as 10hp difference on engine dyno between different oils and those 2 are at the top next believe it or not is valvoline maybe john laws was onto something yes Royal Purple is more expensive but has service life off 30000km same as Redline i will also change gearbox and diff oil before rego sorry did not finish what i was writing this morning had to run

 

[Styria]

Hi motec6.9, this is my point - the 15K. kilometer change was to remove Mobil 1 that I was using at the time - we are going back a few years now. In my view, there is no doubt that an 'old' engine will produce discoloured oil far more readily than, say, a new engine and I would be reluctant to keep any oil, no matter how good or expensive, in the engine for a period to equal thirty thousand kilometers.

Mind you, it is very interesting what you say about the extra 10 horses - it is almost impossible to believe. Regards Styria

 

[motec 6.9]

Hi Styria i dont intend to change the lenght off my oil changes but that is what the makers off those 2 oils claim is the life off there oil but seeing as you asked back in the dark ages ie the 90's a magazine called performance street car did a dyno comparison with a renowned engine builder with all the top oils on the market on a engine dyno recording horse power oil cosumption and contamination of the oils and various other test at the time and the difference between the top syn oils and brand name mineral was just over 10hp on the same day same dyno same engine interestingly there was only .5hp between the top 3 and less than 2 hp between the top 5 once away from pure syn oil hp dropped noticably when back home i will look for the article if you want as in my shed i have every issue off performance street car /streetmachine /wheels from 78 motor manuel mmotor and all issues off car australia kind off sad really

 

[Lukas]

Thanks for the feedback all. I think I'll try for a mainstream full synthetic, with a fallback of a semi-synthetic 15W50-ish if the wallet can't cope.

Will go with the yearly change interval, but that of course may change depending on how dirty the stuff that comes out is after the first year.

Styria: I had not even thought to drain the oil cooler - thanks for that.

Lukas

 

[SELfor50]

I've been recommended Redline by a number of credible sources too. Will be moving to Redline synthetic for my next change for sure. For ATF also.

Cam.

 

[motec 6.9]

Just as an aside Eddy Tassone runs Redline in his cars from Active automotive 1895 rwhp holden 383 stroker with twin turbos and over 800rwhp in naturaly aspirated ls stroker in hsv coup'e and some of the the fastest drag cars in the US and Australia use Royal Purple plus nascar and bonneville racers i decided to be different that is why the Royal Purple over Redline as my engine builder stated that they are his 2 choises and he has not seen lower micro particles in oil test after dyno runs and break ins on engine dyno that with those 2 products so each his own both at the top off the game