Informed opinions on this supposed mechanism of oil consumption?

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Obviously there are a lot of possible ways oil can be consumed. What do we think of this one?

The person who posted this claims it's from a conversation with BMW's no. 1 tech in the US about oil consumption in the S65B40 V8 and the S85B50 V10. Both engines have redlines over 8k RPM and specific outputs over 100 hp/L. The V8 was developed from the V10; they are very similar on the inside.

Assuming the post is genuine, I'm sure something was lost in translation, and the poster is clearly an amateur. Still, there seems to be enough here to evaluate. Can someone with real technical knowledge comment on whether this seems like a reasonable idea about how oil consumption might occur?
oil breaks down at certain temperatures and pressure inside our motors (any motor) and during the oil break down process, certain chemicals (toxic and non toxic) are released. This coats the inside of the piston housing with a kind of slick surface. The dirtier the oil, the slicker the surface becomes and the thicker the coating is on the housing.

...

Our motors... are extremely high revving and if you don't drive the car at the limit the way it was intended and you just lope around town at 2,500 RPM the rings never seat properly due to the fact the oil never gets hot enough to evaporate in the housing, as a result the piston doesn't ride the inside of the housing the way it was intended to, instead it rides on the slick surface coating the housing left there by the oil as it breaks down. This causes oil leak down and seepage and is basically the reason for high oil consumption in the V8 and V10.

Our motors require intense, high revving usage for long periods of time such as on a race track or extended high speed driving in 1st, 2nd, and 3rd gear to heat the oil to the point of evaporation to prevent the coating of the housing.
Source: https://www.m3post.com/forums/showpost.php?p=23360100&postcount=1
 
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I was told a long time ago on a new 350 Chevy engine (flat tappet) the first 50'sih miles drive it easy but don't lug it, under 1000 RPM. After that start leaning on the throttle a little more as the miles add up. During this time, put in 2nd gear, auto or manual, bring the RPM up to 2500RPM and snap the throttle closed. This caused engine vacuum to go up and pull oil up into the cylinders to wash the break-in material off the cylinder walls. When I had my last 440 MOPAR built, .060 over, balanced and blue printed, the engine builder told me basically what I just said PLUS. . . . . .DON"T lug it and keep it between 1500 and 4000 RPM when driving. Red line was 6600 RPM. He said shift it at 6200 RPM when I got on it. It had a high pressure/high volume oil pump, to use conventional 10W30 oil. He stressed don't lug it, its a Hi-Po motor and built that way. He said it should use about 1/2 qt per 1000 miles, which it did. So yes these Hi-Performance motors like to be wound up, "if" they're built that way.
So I can see what the BMW tech guy was saying. Sorry so long of post, but I like to explain things.
 
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Hmmm I'm not quite following him and I've never heard of this. Something was lost in translation. Is he referring to engine break-in?

"Essentially what happens is that the rings on our motors do not seat properly and it allows for the oil to blow past the rings. I asked how is this possible? I mean, isn't this a bad *** super high performance engine built by the best sports car company on the planet? Why would the rings not seat properly?

His answer floored me..first off, yes this engine is an incredibly powerful motor BUT it has extremely low tolerances and actually requires that it be driven at or near red line for extended periods of time!
I was intrigued now...did the top tech in BMW just tell me to go drive my car at its limit because that is going to help my oil consumption?? NO WAY!

Here comes the technical part; oil breaks down at certain temperatures and pressure inside our motors (any motor) and during the oil break down process, certain chemicals (toxic and non toxic) are released. This coats the inside of the piston housing with a kind of slick surface. The dirtier the oil, the slicker the surface becomes and the thicker the coating is on the housing."
 
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a duh yeah oil breaks down and gets thicker but where is the oil consumption angle? I guess there rings and cylinder sizing suck?
 
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Obviously there are a lot of possible ways oil can be consumed. What do we think of this one?

The person who posted this claims it's from a conversation with BMW's no. 1 tech in the US about oil consumption in the S65B40 V8 and the S85B50 V10. Both engines have redlines over 8k RPM and specific outputs over 100 hp/L. The V8 was developed from the V10; they are very similar on the inside.

Assuming the post is genuine, I'm sure something was lost in translation, and the poster is clearly an amateur. Still, there seems to be enough here to evaluate. Can someone with real technical knowledge comment on whether this seems like a reasonable idea about how oil consumption might occur?

Source: https://www.m3post.com/forums/showpost.php?p=23360100&postcount=1

I think that the problem is that the person who posted the information has virtually no idea about how an IC motor operates- which exacerbates any translation errors.
 
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I'm sure there must be a bit lost in translation...

I will say that the S85 in our M6 doesn't use any oil (Redline 10w60) to speak of between changes. But it is changed mostly based on time, as the car is driven only occasionally. But it also sees redline every time it's driven, after the engine reaches full operating temp.
 
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So, basically their cylinders show glazing (kind of varnished / lacquered bores). Oils sometimes were deemed too good for the purpose (much idling / low loads), he instead said that their engines were too good. Perhaps the combined engineering of both is what the customers can't keep up with on public roads.
 

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So, basically their cylinders show glazing (kind of varnished / lacquered bores). Oils sometimes were deemed too good for the purpose (much idling / low loads), he instead said that their engines were too good. Perhaps the combined engineering of both is what the customers can't keep up with on public roads.
This is pretty much how I interpreted the post. It seems to have a lot in common with this description of cylinder wall glazing.
 
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Can someone with real technical knowledge comment on whether this seems like a reasonable idea about how oil consumption might occur?

Yes and the answer (literally) is no for two very important reasons.

Engines don't eat so there is no such thing as oil "consumption"- the oil either changes state ( but still there, just a change in fluid volume) or it leaks out (no longer physically in the engine) so that term would have to be defined in terms and context with specifics for it to be measured in any meaningful way.

Same thing with ring "seating". Mechanically speaking a ring doesn't "seat" against anything- it simply is a hard ( resistant to deformation) metal edge riding in a mixed boundary run over a range under a constant tension ( the ring expansion) coupled with combustion pressures.

The ring is "evergreen" in this process so it never "seats" ( continuous process of seating) and any initial wear is taken care of in a few strokes.

What it sounds like is someone who does have a deal of knowledge speaking above his skill set
 
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It’s funny but I have had a “friend” that worked as a BMW factory rep (basically what this guy is in the link), he was part of our advisory board at a technical school I work at. Nice guy, knows his stuff, but in all honesty I take most of what he says with a grain of salt. He is not some automotive super genius and he is not some sort of mechanical engineer. He IS the guy they call to come in and fix issues that the techs can’t figure out at the dealer, however he has a slightly different take than I’m reading with this guy. Here is some excerpts of conversations of had with him...

If you buy an older twin turbo 5 series you will have that thing in the shop every single month, I can’t even fix that thing. BMW bought the factory that makes the high pressure fuel pumps and even we haven’t figured it out.

What he was told from someone higher up than him in BMW — Our cars are designed to last 100,000 miles, after that we don’t care, our true customer base does not hold on to these cars for more than half that, then they buy or lease a new one. Stop worrying about longterm reliability, it doesn’t matter.

The V8’s are a complete nightmare. Half our shops are rebuilding or replacing them at 50,000 miles. Total junk. Rings are junk. Oil consumption. Stay away from the V8. If you buy a V8 I’ll never talk to you again.

The 7 series are one of the top ten worst cars ever made. Electrical night mares - then he showed me a YouTube video of someone beating their brand new 7 series to death right in front of BMW, before leaving it there and walking away from it.

Now all of this ^^^ is just shop talk between us and I haven’t seen the guy in three years, but he was a good guy and knew his stuff. He did love BMW’s and owned a super high mileage (much older M5).
 

d00df00d

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Yes and the answer (literally) is no for two very important reasons.

Engines don't eat so there is no such thing as oil "consumption"- the oil either changes state ( but still there, just a change in fluid volume) or it leaks out (no longer physically in the engine) so that term would have to be defined in terms and context with specifics for it to be measured in any meaningful way.

Same thing with ring "seating". Mechanically speaking a ring doesn't "seat" against anything- it simply is a hard ( resistant to deformation) metal edge riding in a mixed boundary run over a range under a constant tension ( the ring expansion) coupled with combustion pressures.

The ring is "evergreen" in this process so it never "seats" ( continuous process of seating) and any initial wear is taken care of in a few strokes.

What it sounds like is someone who does have a deal of knowledge speaking above his skill set
Not sure I understand. Are you dismissing the explanation out-of-hand for incorrect terminology, or is there a deeper reason?
 

d00df00d

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It’s funny but I have had a “friend” that worked as a BMW factory rep (basically what this guy is in the link), he was part of our advisory board at a technical school I work at. Nice guy, knows his stuff, but in all honesty I take most of what he says with a grain of salt. He is not some automotive super genius and he is not some sort of mechanical engineer. He IS the guy they call to come in and fix issues that the techs can’t figure out at the dealer, however he has a slightly different take than I’m reading with this guy. Here is some excerpts of conversations of had with him...

If you buy an older twin turbo 5 series you will have that thing in the shop every single month, I can’t even fix that thing. BMW bought the factory that makes the high pressure fuel pumps and even we haven’t figured it out.

What he was told from someone higher up than him in BMW — Our cars are designed to last 100,000 miles, after that we don’t care, our true customer base does not hold on to these cars for more than half that, then they buy or lease a new one. Stop worrying about longterm reliability, it doesn’t matter.

The V8’s are a complete nightmare. Half our shops are rebuilding or replacing them at 50,000 miles. Total junk. Rings are junk. Oil consumption. Stay away from the V8. If you buy a V8 I’ll never talk to you again.

The 7 series are one of the top ten worst cars ever made. Electrical night mares - then he showed me a YouTube video of someone beating their brand new 7 series to death right in front of BMW, before leaving it there and walking away from it.

Now all of this ^^^ is just shop talk between us and I haven’t seen the guy in three years, but he was a good guy and knew his stuff. He did love BMW’s and owned a super high mileage (much older M5).
Oof.

Doesn't sound like he's talking about these engines here. This all sounds like the N63. The pain is super real with that one.

Not that BMW V8s generally don't have their problems, but none of them had problems like the N63.
 
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Not sure I understand. Are you dismissing the explanation out-of-hand for incorrect terminology, or is there a deeper reason?

A deeper reason and in my experience, terms like "consumes" ( or whatever) is too often used to excuse or mask a greater issue. ( sometimes to the point where its even viewed as "normal" or even "by design")

A total loss system like way lubrication "consumes" an oil, a mixed gas ICE "consumes" oil- a closed system doesn't. (now obviously this is not counting the token amounts lost from a vent or possibly in range of combustion on an ICE and seal weepage which is statistically over a normal change range insignificant)

So with that being the baseline, that guy's "diatribe"/reason/explanation ( embellished, misinterpreted or otherwise) which is not based in anything but anecdotal logical deduction is just "excusing away" something that indicates a defect that should be addressed.
 
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Would you mind addressing what most people refer to (write off?) as glazed rings or cylinders? It can be in a separate thread if you like.
 

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Maybe it's better to paraphrase the idea. AFAICT, it's this:

1. At low loads/RPMs, the engine allows deposits from oil breakdown to accumulate on the cylinder walls
2. Those deposits, when present at high levels, can prevent the oil control rings from functioning as well as they otherwise would
3. This poor oil control ring performance allows oil to be burned and/or ejected via the exhaust at abnormally high rates
4. Sustained periods of high load and RPM can reduce those deposits, thus restoring some of the ability of the oil control rings to function as intended

Yes? No? Why or why not?
 
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there are a lot of factors for sure BUT as noted you need to get the rings properly seated from NEW + low RPMs lower heat will not do it!!! my new to me 13 Victory Hammer 106 cu in air-oil cooled bike bought in 13 with 600 miles on it was using oil, 2 qts in a few hundred miles after purchase SOOO as i had seen on line i took it on a back road + run it up to 4 thou RPM in 3rd gear then normal for a bit, redline is 5500 +after several drives doing this on a few rides oil consumption ceased + today uses NO oil, it worked for me!!! MR Subaru a dealer tech you tubes note things like low tension rings etc used today has contributed to oil consumption on todays well made but produced engines + many times WE are the BETA testers that sort out new "teething" problems with new tech + designs TRYING to better meet the emissions + mpg requirements!!
 

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I'm pretty sure this isn't talking about break-in, but about something that can (supposedly) happen at any point in the engine's life.
 
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Maybe it's better to paraphrase the idea. AFAICT, it's this:

1. At low loads/RPMs, the engine allows deposits from oil breakdown to accumulate on the cylinder walls
2. Those deposits, when present at high levels, can prevent the oil control rings from functioning as well as they otherwise would
3. This poor oil control ring performance allows oil to be burned and/or ejected via the exhaust at abnormally high rates
4. Sustained periods of high load and RPM can reduce those deposits, thus restoring some of the ability of the oil control rings to function as intended

Yes? No? Why or why not?

Maybe. What is unique about (only) certain BMW engines which makes this a certainty?
 

d00df00d

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Maybe. What is unique about (only) certain BMW engines which makes this a certainty?
I don't think anyone's saying it's a certainty; just that it can happen. But yeah, this is a good question.

Not sure if what's being described here is bore glazing per se, but if it is, it's theoretically a problem in any engine -- though most of the conversation about it is in the context of diesel engines that see a lot of idling and low-load usage. Other engines don't seem to be particularly vulnerable to it.

What's unique about these engines? I don't know details, but these are definitely unique engines. The V10 was an all-new design derived from a Formula 1 engine; the V8 is the same design with two cylinders chopped off and few updates. Neither is related to any other BMW engine.

I wonder if oil is a factor. These engines use a race-bred 10W-60. That's far from standard fare for normally-driven street engines.
 
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I suppose it depends upon what the actual reason for the oil burning is. I am very skeptical of the story from the tech referred to in OP.
 
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