0W-40 and Potential Rod Bearing Wear....0W-50 on the Street?

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8,048
Location
Michigan
I doubt a wide viscosity spread oil will give you the "film strength" the numbers show. I can't guess a band aid for a poorly designed engine will be oil but others may chime in. Do the BMW specific boards give and advice?
As a matter of fact, wide viscosity spread works against film strength.
 
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53
why not try a redline oil? arent they supposed to be using the best synthetic base oils and kinda meant for racing and high rpm? bukra phoosi
 
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11,663
Location
Colorado Springs
why not try a redline oil? arent they supposed to be using the best synthetic base oils and kinda meant for racing and high rpm? bukra phoosi
Track and racing is not same as street use.
Redline is not doing favor to anyone claiming their oils "meet and exceed" LL01 etc. bcs. they do not. Redline targets track crowd etc. but their oils would never meet oxidation requirements of BMW precisely bcs. composition of oil is suitable more for a track than street.
Motul is more transparent on this issue. They clearly state that their Ester oils, that they target for racing, track, are not approved, or meet and exceed, and they basically say: you figure out when to change it and how to use it.
 
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3,784
Location
WI.
motor oil can't overcome poor engineering...interesting conversation though, glad I don't have a need for fast.
 
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1,939
Location
Ontario, Canada
I have to admit I was thinking of the V8 S65 when I made my previous post. I didn't think the S55 has bearing problems, but I could be wrong.
The S55 is based on the N55 which does see bearing issues. I don’t think it is simply an oil issue. I have a feeling it may be related to the variable displacement oil pump. BMW does not even know why yet.
 
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1,088
Location
TX
I use Red Line in my non-daily drivers... S2000, NSX, SC400. All see the track. All get their oil changed once a year. UOAs come back fine. They seem to survive. Of course, there is really no way to know if some other routine would be better.
 
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11,663
Location
Colorado Springs
The S55 is based on the N55 which does see bearing issues. I don’t think it is simply an oil issue. I have a feeling it may be related to the variable displacement oil pump. BMW does not even know why yet.
I think rod bearing issue is mostly connected to poorly done job on OFHG and no priming procedure.
 
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