Question on Oil 2008 E63
 

I just did my yearly Oil change. I used Mobil 1 0W-40 with OEM filter. I recently read that "now" the recommended oil for the M156 is 5w-40. Will I be ok with leaving the 0w or should I change it to 5w? I don't want any engine problems or premature wear from start up. I leave the car sit for days at a time. I really only drive it on weekend. Any thoughts would be appreciated.

You need not to worry...both weights work well...

OK Thanks
 

Weistec confirmed the same as well.

i went from Motul 6100 5w-40 to Mobil 1 0W-40 and it feels SLOWWWWWWER.

Motul is double the price though.

???? I just had my intake gaskets replaced, and only issue was literally a sludge , sticky oil on the ports. Nasty sticky crap and the tech didnt know where or why it was there. All around the ports, doesn't seem to be causing any issues, but brought questions. Any ideas of how to rid the system of that???

Yearly oil change? Even when my car sits in a garage over the winter I change the oil at least once in that time period.

Where did you read that 5w40 is the correct oil? It is my understanding that a few years ago MB changed the recommended oil to the 5w40, which is an emissions focused formulation primarily intended for diesel motors, but quickly changed it back to the 0w40 for M156 and other petrol engines. The 5w40 wasn't providing sufficient protection possibly due to ethanol dilution from US E10 fuels, which the 5w40 is more susceptible to. Apparently some of the dealerships either didn't get this memo, or just didn't care because it's easier and cheaper for them to stock one oil rather than two different oils (diesels absolutely require the 5w40). I looked at the data sheets for both, and I think the 0w40 is the better oil unless you are interested primarily in emissions system performance.

I cannot say before 60k miles, but between 60-90k miles its had 4 or 5 changes, but could have easily been sitting for a period before I got it, the sludge is on both sides of the intake ports, wipes off but stringy gooey stuff, so we didnt clean it all off. Just didnt know if an additive of some type might help clear this up PIC below of the crap.

http://imagizer.imageshack.us/v2/xq90/540/u0Iox7.jpg

I'd say both of those oils are fine. But be careful when ordering 5w 40. They also come in a turbo diesel truck format...don't ask me how I know.

and as for sludge. Sheriff... yours looks world's better than my e39 project car. It's literally made me stop spending any money on it cosmetically for fear of the engine crapping out. I don't think the previous owner knew what oil changes were.
https://cimg7.ibsrv.net/gimg/www.mbw...4c4b3b555d.jpg

I've run thru 2-3 oil changes in 1,500 miles

^^^^^^^^^This is the truth^^^^^^^^
That 5w40 switch happened years ago, same time as all the cam problems in the M156.