WHICH OIL FOR E39 M5??

Absolutely,

Its LL01 approved.

Cheers

Simon.

PS:  a TWS 10w60  is a 10W base oil.  it only acts like a 60 W

oil at 100C.  go buy a 1L  and see how thin it is yourself.

John

The issue is the viscosity that the design requires in stock road cars.

At 100degC oil temps they are as follows:

SAE 30 = 11cst

SAE 40 = 14cst

SAE 60 = 24cst

If the car requires sae 30 or 40 and an sae 60 is used there are several consequences that can occurr.

Poorer fuel consumption.

More viscous drag and therefore lower bhp.

More friction, heat and wear.

The risk of air entrainment if oil temps are too low, causing slugs of air to be fed to bearings. 

An sae 60 would need to run an oil temperature of around 140degC to be the same viscosity as an sae 30 at 100degC and around 128degC to be the same viscosity as an sae 40 at 100degC.

At an oil temperature of 90degC the oils would be these viscosities

SAE 60 = 30cst

SAE 40 = 16cst

SAE 30 = 12cst

It's your car, use what you like but unless sae 60 is specified or there is a good technical reason (high oil temperatures being the logical one) I would not use it personally.

Cheers

Simon

John,

I am not taking any technical issue at all with you as you clearly know much more than I do. I only make the point that BMW's own technical bulletins are clear that they recommend TWS only up to Feb 2000 S62 engine builds and then LL-01 0/5w-30/40 thereafter. Owners' manuals are equally clear.  The issue is that many service departments don't read the technical bulletins and therefore fill with oil that is not the recommended one for that car especially when the service indicators don't tell you an oil change is due for about 15,000  miles!!

I acknowledge that this is for the mass market consumer, and presumably also for warranty reasons.  The knowledgeable enthusiast will always have the ability to use what he feels and knows from experience is the most appropriate oil for his car for his purpose - as do you.  I am all for this.

STEPHEN B

yes it is.  call BMW motorsport and ask.

John

There is nothing wrong with using TWS, that is not a "miss-fill".

It is the superior oil.  All the M5 owners at the Ring are running it

as well as people who run M5 engine in race cars.

I dont know what is so difficult to understand, there are no

engineering reasons that speak against TWS.

John

Yes!!!  Unless they had misfilled it with TWS at the last oil change in which case it won't make any difference!  Look in your manual!

Stephen B.

Yep, your free to take your own oil.

Cheers

Simon.

harvard468 wrote: Adam, I'm very surprised at this because last July (2004) when I was getting nowhere I rang Damon Hill and they got it right as did Dick Lovett in Bristol!! Maybe you got a different Service Agent who didn't bother checking his tech specs! Regards STEPHEN B

Stephen

I contacted Damon Hill on Friday, after questioning the 10-60 the chap I spoke to did go and check it out, he phoned me back as good as gold and confirmed that the 10-60 is not the correct oil. As you say perhaps its down to different service agents.

At least I now know which is the correct oil and I know that Damon Hill also know - its a relief !!!

Thanks again !!!

still looking... :)

but while looking I saw a few other things, Ill post here too:

-- the GTR was also using TWS in the latest 24h race at Ring. This oil also in GT3.

-- on race engine be VERY careful when making any assumptions why they may or may not use a light(er) viscosity oil.

-- on a race engine, you dont need a huge additive package which is what "long life oils" have. additive packages do nothing for your bearings, they just stabilize the oil. So this might be a consideration for someone that intends to run WOT for extended periods on track. If you are an environmentalist, perhaps it is important to you to keep the oil in service as long as possible. If you are primarily interested in your engine, changing oil based on your (track) use may have priority.

anecdote: in the late DTM days, BMW motorsport reached rpms up to 10500 rpm. They switched to a lower viscosity oil, I dont know the type or the rating but I was told by BMW motorsport this was so. It was probably a special formulation not available to the mass market. If it is of real interest, I can ask on tuesday at Motorsport the exact spec just so we know. The reason this came up was because I was investigating differences in 2 different DTM cranks.  One had 1 oil supply per rod journal and the other crank had 2 supplies per rod journal.

This might be obvious to some of you guys but not to all, and since its important, let me explain: when we go up in the revs we like to ensure high oil pressures. The usual rule of thumb is about 1 bar per 1k rpm. So at 8k rpm that would mean 8 bar oilP! This is not really easy to achieve and requires modification of the oil pump (we are talking about a wet sump engine). Obviously, this also cost a bit more loss which you can add to your over all power loss budget for your engine. According to BMW research papers, increasing oil pressure up to about 8 bar sill makes sense, but after that it does not make sense to further increase oilP. IOW, even with 12 bar oilP you could not protect your engines from rod bearing damage at very high rpm; you have passed the point of diminishing returns.  The solution to this problem is to increase the number of oil supply passages at the bearings, and it can not be done in just any fashion (various configurations are possible, not all effective).  BMW Motorsport did exactly this on the late DTM cranks, and when this happened they no longer required such high oil pressures nor high viscosity because they have increased the fluid flow or lubricity.  This little change made the price of the crank jump from 2000 euro to about 3500 euro :)

John