Oil consumption has nothing to do with rod bearing wear.
I keep reading post after post about guys who changed the rod bearings and then report that oil consumption is less. Little do they know that rod bearing do not eat oil. In the shortblock (bottom end), oil is usually used up through the piston rings and not the rod bearings. In the top half of the motor, oil is usually used up through the valve stem seals.
Agreed. I do think it is odd though that some of these engines will burn alot of oil and some will burn very little. Mine stopped burning oil at 20k miles. Before that I had to add a liter between changes.
Some oil consumption is normal in every engine, although some use more than others. I have 104K miles on my 2006 and I use roughly one quart or so between oil changes...I change oil roughly every 6K miles. I use either Mobil 1 10w-40 or Castrol 5w-50 oil...I never, ever used the factory recommended TWS 10w-60, and I never followed that goofy 15,000 miles oil change interval...not even on my wife's 550i sports package.
For those who do not know, many of those rod bearing shots posted looked normal...yes, this may come to a shock for most of you. No rod bearing on this planet will appear blemish free after a few thousand miles. 99% of your engine wear occurs during start up, so if you want to help your engine live a good live, then use a good quality synthetic oil that circulates really fast to all critical engine parts. A 0w-40 or 5w-50 works just fine, but if you cant find either, a 10w-40 will work just fine. Remember, these are multi viscosity oils - W for winter (meaning, it will flow well at 0* or 5* or 10* degrees) and the last number (40 or 50 or 60 weight) indicates thickness once it is heated.
A little thinner oil will provide a more audible engine valvetrain noise, but it will flow much better especially in the cold or when the engine is cold like in the morning. Remember, just because you live in a desert or in hot climated, it does not mean that you should use thicker oil...keep in mind that most of engine wear occurs during start up and as long as your engine/oil does not run super hot, then oil breakdown is less likely to happen...viscosity breakdown hurts your rod bearings much like low oil psi. Another thing, do not follow BMW 15,000 miles change intervals, that is total BS IMO.
Hope this helps