Re: R1100S questions

[Robert Silas <robert.silas@xxxxxxxxxxxx>]

Tom, 
I have them both, the RS and the K75s. The RS has 170,000 km and does not need oil between oil changes ( I try to mange oil changes at every 5,000 kms), however the "K", a beautiful engine, has 45,000 km and require adding oil between oil-changes. I am using Motul 15-50 since day one.
Bob Silas
  ----- Original Message ----- 
  From: Tpcutter@xxxxxxx 
  To: oilheads@xxxxxxxxx 
  Sent: Monday, September 26, 2005 2:44 PM
  Subject: Re: R1100S questions


  In a message dated 9/26/05 1:49:48 PM Eastern Standard Time,
  Rene-didier@xxxxxxxxxxx writes:
  I use the BMW oil in my R1100S. The BMW store  recommends it, my independent
  mechanic (BMW trained) recommend it, and the cost  is reasonable.>>

  I have been selling and using BMW oil off-and-on  for 15 years. Currently I
  have no source of it close enough that shipping cost  is not a major issue, so
  I started running Castrol Syntec Blend in my R1100S. No  problem, but I was
  seeing about 1 quart every 1400 miles of consumption. Not a  real issue, but
  the
  level would often drop low while away from home which meant  carrying a
  supply of oil with me.

  I tried one change with Mobil 1 (notice  that there is no E in MOBIL)! Gold
  cap, and noticed that consumption seemed  about the same, but vibration and
  engine noise went up noticeably. The oil  "feels" thinner (less viscous) at
  any
  comparable temperature.

  So I got a  case of BMW oil that I had ordered for a client who never picked
  it up, and I  started using it in my R1100S. The consumption has dropped to
  around 1 quart in  2400 miles, (it is so hard to really quantify that with the
  hinky oil level  issue) and the engine is smooth and quiet like it was with
  the
  Castrol.

  Here's my OPINION, based on years of  observation:

  1) I THINK that Mobil "cheats" the  viscosity ratings of their oils to
  achieve superior startup and mileage numbers.  It is well-established that
  lower
  viscosity oil will give slightly improved fuel  mileage, and cold starting is
  naturally enhanced by lower viscosity  oil.

  2) I KNOW for fact that the powers-that-be at  Mobil remember all too well
  the issues with Mobil 1 oil and BMW Airhead engines  in the early seventies,
  when the ONLY variety of Mobil 1 oil being marketed had  NO viscosity marking
  on
  the label. When pressed by BMW, Mobil admitted that the  oil was in fact a
  5W30 viscosity blend, and the Airheads required a MINIMUM  10W40 or higher in
  hot
  weather. The lack of viscosity caused several  well-publicized BMW motorcycle
  engine failures.

  For  this reason, I am not surprised that the Mobil engineer was not trying
  to "sell"  you too hard on their oil.

  3) It is VERY difficult to  find a steady supply of Mobil 1 15W50 oil at many
  stores. You have to read EVERY  container carefully I often find the 5W30
  mixed in with the 15W50 on the shelves  in many auto parts stores. Your
  Oilhead
  MUST have the 15W50 Mobil 1, even in the  winter time. In fact, that would
  probably be a good choice for winter oil in  northern regions where
  temperatures
  can dip into the teens or twenties (:F)  overnight and cold starting becomes
  an
  issue. I would not recommend the Mobil 1  for hot weather use in any BMW
  except the K models. (I almost think you could  weld the drain plug shut on a
  K
  model and they would keep  running.)

  Again, these are my OPINIONS, based on my  OBSERVATIONS. I ain't* no oil
  engineer, and don't want to become one.

      * When I tried to spell-check this post, this is  what it told me for
  "ain't": "Nonstandard words and phrases might be appropriate  in very informal
  speech, but you should avoid them in writing.  They can  annoy your reader and
  detract attention from what you are trying to express." I  apologise in
  advance
  for any annoyance...

  Tom Cutter
  Yardley,  PA
  http://www.RubberChickenRacingGarage.com

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