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I for one will do a proper warm up, regular 3000k oil changes and enjoy may car the way it was meant to be driven and change my rod bearings. As for the oil temp it is regulated and the viscosity difference will have little effect when the oil is hot as Falco points out.
Yup we all agree to disagree and that's fine. What's your warm-up routine? I start my car and go. I stay away from the rev limiter when cold and that's it - just common sense. And I do 10k OCI using TWS and before covid used to daily drive my car including midwest winters. Are you still using 5w30? I wouldn't do the same but there's evidence that 10cst means little.
 

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That's exactly my point. You're worried about a 10cst change. A 100x greater change occurs as oil goes from cold to hot. Yet no one would argue that's not ok. Sure if you take this to the extreme and consider water at 1cst then you have a problem. But those discussions are for the energy vampires.

And there will be little to no effect on pressure with a 10cst change unless at idle or on a worn engine with loose clearances. Flow is greatly increased when hot but temperature and pressure won't tell you that.
I am not worried about cst at all. I didnt look at it when i switched from w30 to w40 and let that dictate my decision. I looked at real life numbers only and didnt like my w30 hot temps at 225-235f at operating temps in daily driving nor my pressures at wot to redline. Switching to heavier oil helped w both; decreased temps and increased pressure.

All i am saying that there definitely is a real life difference between w40, w50 and w60. Without knowing temps or pressures, we are participating in an exercise in mental masturbation instead of looking at real life data.

My intuition based on my experience tells me w60 is too thick for daily driving, but its an assumption. Obviously there is a bearing issue on these cars and i cant deny my brain wants to blame the oil of choice first. Wish someone had real life data of pressures at 8000rpm at wot at operating temps.


..but there's evidence that 10cst means little.
What evidence? And what do you mean “means little?” I have real life evidence that from w30 to w40 hot pressures went from 55 to 65 psi. Thats not little to me. What it does at cold temps is irrelevant really.
 

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I am not worried about cst at all. I didnt look at it when i switched from w30 to w40 and let that dictate my decision. I looked at real life numbers only and didnt like my w30 hot temps at

My intuition based on my experience tells me w60 is too thick for daily driving, but its an assumption. Obviously there is a bearing issue on these cars and i cant deny my brain wants to blame the oil of choice first. Wish someone had real life data of pressures at 8000rpm at wot at operating temps.
Why would BMW specify 10w60 for the s85 engine? They have been making engines for approximately 100 years? (Including ww2 luftwaffe fighters). I'm happy to concede that you are more knowledgeable than me, but really for the general non-engineering background driver like me, the BMW recommendation is going to be pretty much cast in stone.
 

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@Ishi .. why would BMW make an engine with failing rod bearings? 🤷🏻‍♂️

Not everything goes as planned, always. To add, why do you accept what they say about oil weight but dont accept their oil service interval which I’m sure isn’t 3000km/mi?

Something somewhere failed, unless they intended for the bearings to fail <100,000. I am not saying its the oil though thats the problem, for the record. But something’s up.
 

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@Ishi .. why would BMW make an engine with failing rod bearings? 🤷🏻‍♂️

Not everything goes as planned, always. To add, why do you accept what they say about oil weight but dont accept their oil service interval which I’m sure isn’t 3000km/mi?

Something somewhere failed, unless they intended for the bearings to fail <100,000.
I get what you are saying. (Just to clarify my oci is according to obc or every 2 years, definitely not 3000km. I think the 3000km oci is another member). I'm still unconvinced that the s85 has a general underlying rod bearing problem (my opinion :)

To each his own. You may be right and your regimen/choice of oils may keep your engine in better condition than usual / lower the failure rate ( I hope so as a fellow M driver :)

I'm just saying that there are so many data points. Short of conclusive evidence demonstrating that a particular viscosity/oil pressure is better than factory recommendation, I would hazard a guess that the majority of drivers out there will just go with the factory recommendation.
 

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I am not worried about cst at all. I didnt look at it when i switched from w30 to w40 and let that dictate my decision. I looked at real life numbers only and didnt like my w30 hot temps at 225-235f at operating temps in daily driving nor my pressures at wot to redline. Switching to heavier oil helped w both; decreased temps and increased pressure.

All i am saying that there definitely is a real life difference between w40, w50 and w60. Without knowing temps or pressures, we are participating in an exercise in mental masturbation instead of looking at real life data.

My intuition based on my experience tells me w60 is too thick for daily driving, but its an assumption. Obviously there is a bearing issue on these cars and i cant deny my brain wants to blame the oil of choice first. Wish someone had real life data of pressures at 8000rpm at wot at operating temps.



What evidence? And what do you mean “means little?” I have real life evidence that from w30 to w40 hot pressures went from 55 to 65 psi. Thats not little to me. What it does at cold temps is irrelevant really.
The e60 isnt designed to be pussy footed around
Its meant to be at 100 deg plus oil temps each drive
In my experience regardless or maintenance, cars driven softly that are performance based have more issues
 

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In my experience regardless or maintenance, cars driven softly that are performance based have more issues
I agree except for the ‘regardless of maintenance part’. Poorly maintained hard driven cars end badly just as poorly maintained babied ones.

But definitely cars driven softly and rarely seem to suffer more issues than those driven regularly and spanked often.
 

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I am on 10W30 Mobil at about 3000mi changes. Nothing over 3000rpm until the oil is up to temp. Oil is cheap and if I have to wait a few minutes too hit it I will survive. Street or track I really haven't had any huge problems, the biggest one is the software not the hardware. If you do a little math on the revs/mile you will get a more concrete answer than guessing about oil types, weights and bad design.

Hot oil is hot oil for the most part. We heat our fuel to control the viscosity before we feed it to the engine. 12-15 is ideal but we go as low as 2 and as high as 20, the temperature difference is small. The engine keeps running. I think the biggest difference is cold start up. If you live in an area that gets really cold you should run a lighter oil for better flow during start up when most wear occurs. In a moderate to warm climate run what you like. On a forum of engineers that discussion will never end but that will not stop us.
 

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OMG. Just reading through all this...my brain hurts. I'm just going to stick to what my car has always known. Castrol Edge 10W60. Warm up period from cold start, nothing over 3k until engine oil is up to temp...then STOMP STOMP STOMP.
 

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OMG. Just reading through all this...my brain hurts. I'm just going to stick to what my car has always known. Castrol Edge 10W60. Warm up period from cold start, nothing over 3k until engine oil is up to temp...then STOMP STOMP STOMP.
Total agree...but....before some days need to change oil at dealer and told me that BMW stop the Castrol for all M's |(also M5 E60 ) and now use the own labeled M Twinpower 10w60.
The label says Shell and from a quick search is Shell Helix Ultra 10w60. The specs is same with Castrol .
We use the new "recommendation " or not????
 

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2008 E60 M5 Dinan S2+
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Total agree...but....before some days need to change oil at dealer and told me that BMW stop the Castrol for all M's |(also M5 E60 ) and now use the own labeled M Twinpower 10w60.
The label says Shell and from a quick search is Shell Helix Ultra 10w60. The specs is same with Castrol .
We use the new "recommendation " or not????
Yup. I was told the same thing at the dealership. I'm going to guess, the switch to shell from castrol was a more corporate deal to get better pricing on oil. The specs are the same - all good with me.
 
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