BMW F850GS Forum

Please login or register.

News: A big welcome to all new members !


Author [NL] [FR] [ES] [DE] [SE] [IT] [NO] [MY] Topic: Fuel grade contradiction  (Read 1135 times)

0 Members and 1 Guest are viewing this topic.

Online DaveF850GS

  • GS Member
  • **
  • Posts: 24
  • Bike: 2019 F850GS
  • Town / City: Jacksonville Florida
  • Country: us
Re: Fuel grade contradiction
« Reply #10 on: March 30, 2021, 05:16:38 PM »
Thanks for getting that clarification BMW Motorrad.  Since the F850GS is an "adventure bike" it is smart for BMW to design the engine to use lower octane "regular" fuel.  You can not always guarantee availability of higher octane gasoline in remote areas.  I have a 2019 F850GS it has used nothing but "regular" gasoline since the bike was new and no issues after 10,000 miles. 
The adventure begins when the plan fails

Offline Roadapple

  • GS Member
  • **
  • Posts: 15
  • Bike: 2019 F850GS
  • Town / City: Powell, OH
  • Country: us
Re: Fuel grade contradiction
« Reply #11 on: April 03, 2021, 03:28:31 PM »
Here's an update on my attempt to get clarification from Motorrad.  I went back and forth a couple more times with Motorrad USA without them answering why the difference in what the manual calls for and what is specified on their website.  I also reached out to Motorrad Germany but haven't heard back after several days but they may yet respond.  Motorrad USA did state that any grade of fuel 87 octane or higher will be fine for the engine.  One thing I discovered by online search is that Cycle World did a review of the F850GS Adventure a couple years ago and they stated that the engine makes 95hp@8250rpm on premium and 90hp@8000 on regular.  These figures would be at the crank so I think it's safe to assume they came directly from BMW because no one else would be testing a demounted engine.  The top speed was a few mph higher using premium too.  It seems to me that BMW should state clearly in the manual and on the website that the engine can be run on fuels of various octane ratings with a slight decrease in output using regular gas.  As it is, with the website specifying premium gas, I would think that anyone looking to buy a bike to be used in more remote areas wouldn't consider a bike that could only run on premium.  Here in the US we would call that "shooting oneself in the foot".   :002:

Offline ZigZag

  • GS Member
  • **
  • Posts: 14
  • Bike: F750GS
  • Town / City: Woking
  • Country: gb
Re: Fuel grade contradiction
« Reply #12 on: April 07, 2021, 09:11:12 AM »
Interesting article here explains the difference between RON, MON and AKI and suggests what fuel works best: https://www.bmwmoa.org/news/438324/Understanding-octane--AKI-MON-and-RON-oh-my.htm
Life is what happens when you're busy making other plans.

Offline Roadapple

  • GS Member
  • **
  • Posts: 15
  • Bike: 2019 F850GS
  • Town / City: Powell, OH
  • Country: us
Re: Fuel grade contradiction
« Reply #13 on: April 07, 2021, 10:38:08 AM »
Thanks for the link.  I did finally hear back from Motorrad Germany. I had explained to them that I had contacted Motorrad USA several times and got no satisfactory answer about the contradiction between the manual and the website.  But M. Germany said they would refer my question back to M. USA - so thanks a lot for nothing.  It's a real head scratcher to me that my F850GS manual recommends regular gas with no further explanation.  I intend to ignore what's written in the manual for three reasons. First, their website specifies premium.  Second,  the info from the Cycle World article that I referred to earlier.  Third, the engine has a compression ratio of 12.7 to one which certainly should need premium fuel to run most efficiently.  Up until now I've been running regular with no issues and others have been doing the same so I know it can be done.  If I can't find premium in the future I won't worry about using regular but from now on I will use premium when it's available.

Offline Yorks_Rider

  • GS Pro
  • ***
  • Posts: 102
  • Bike: F750GS
  • Country: de
Re: Fuel grade contradiction
« Reply #14 on: April 08, 2021, 01:00:11 PM »
I checked the BMW Motorrad Germany homepage and this is essentially what it says for the versions sold in Germany.

The F750GS needs 91 RON minimum unleaded (91 RON was previously called "normal" here, but is no longer sold)
The F850GS needs 95 RON minimum unleaded (95 RON is called "super" here)
There is a "special order" version of the F850GS with power reduced to 48 PS (for the A2 class driving licence in Europe) and this runs on 91 RON minimum.

In practice, I run my F750GS on 95 RON fuel because there is no lower octane petrol sold at the pumps in Germany.


Online Matty589

  • GS Pro
  • ***
  • Posts: 372
  • Bike: 2019 F750GS
  • Town / City: Surrey
  • Country: gb
Re: Fuel grade contradiction
« Reply #15 on: April 08, 2021, 01:38:09 PM »
...and there appears to be zero benefit to using higher-rated fuel (e.g She’ll vPower), except for perhaps slightly cleaner engine internals. In fact when I trialled it with my 2018 1200GS it ran so hot the exhaust  as it runs past the flappy valve was kicking out so much heat that it made my right thigh very hot. dealer advised just to use 95RON fuel.