Mobil 1 0-40 may not be best oil for some BMWs
This is just my experience with my 95 525i m50.
I used 0-40 mobil 1 for several oil/filter changes at about 4-5,000 miles each . I have two oil analysis done by Blackstone Labs. Both indicated fairly high levels of lead and some fuel dilution. The reason I went to 0w40 was to reduce valve clatter on the first cold startup of the day. That worked. I have also been told the 0w40 shears down quickly to a 30 weight. Just not sure it is the best for an old engine with over 100,000 miles
I have since switched to Mobil I 5-w40 truck and suv. It has lots of cleaners, does not shear easily and handles high temperatures very well. Plan to have a UOA done soon on this oil.
Just one persons experience

Originally Posted by
Jose
Hi guys,
I´ve just beenh reading on all sort of old posts on our forum and couldn´t help notice that on the oil topic almost all of you run your car on Mobil 0W40 oil, mostly based on other people´s advice or opinion. I can undertsand this if your running a newer engine with hydraulics, but don´t see the point of using this oil with the ´older`type engine like the M30. I myself run these engine on Castrol 10W60 for years now, but would like to hear from you if you run/ran the same engine as mine on other oil than Mobil before changing to Mobil 1 0W40 and noticed changes, positive or negative. So just experiences, no opinions on being better or worse for the engine.
Reason for asking is that we switched to Mobil 1 full synthetic at work last week, so I´m able to get this stuff for free.
Thanks.
Last edited by Russell; 07-21-2005 at 06:16 AM.
Thanks,
1995 525i Auto, M50TU 2.5L, EAT chip, 1/95 build, USA, 205/65/15 tires, ASC+T, HID, lumbar, EC Mirror, BMW Alpine 5 radio with BMW-Pioneer CD Changer, abt 236k miles, Oxford Green/Parchment