BMW Motorcycles: What the Model Letters and Numbers Mean

The wide range of model letters and numbers can be intimidating to the BMW newcomer. Fortunately, the nomenclature is pretty straightforward, making it reasonably easy to master.

Here’s what to initially learn:

  • The first letter tells you the motor configuration
  • The number in the middle tells you the displacement (almost always).
  • The last letter combination (initials or full name) alerts you to the type of motorcycle—though not which line.

With that in mind, let’s dive in a bit deeper—though not into the deep end.


The prefix letter is always the motor. Conveniently, BMW uses the same motor designations across all of its genres of motorcycles.

  • F: This is for parallel twins in the 900 to 750 range. Confusingly, BMW called the 650 single-cylinder motor an F from 2000 to 2007—let us never speak of this again.
  • G: A single-cylinder motor—currently the 310 exclusively, though it has been a 650 in the past.
  • K: In the 21st century, this means an inline-6 that is transversely mounted. Back in the 1900s, it was a longitudinally mounted inline-4. The K continued in the early 2000s as a transversely mounted inline-4. We’re not sure why BMW recycled the K instead of coming up with a new letter for the inline-6.
  • M: The M is the high-performance version of the inline-4 used by the S models.
  • R: The classic boxer twin, these range from the Big Boxer used in the R 18 to the 1170cc R nineT line. BMW’s use of the R dates back to the 1923 R 32 flat-twin, though the R was used for single-cylinder models into the 1960s.
  • S: This is the inline-4 configuration. It’s a one-liter design.


The number is the displacement class. The R 18 leaves a couple of zeros off, and the nineT is an 1170cc boxer.



  • GS: BMW has used this designation for its adventure bikes since the G/S in 1980. GS means Gelände/Straße (off-road/on-road), and Gelände Sport.
  • XR: These are the ADV-style adventure-tourers rather than off-road capable motorcycles.


BMW does things differently for the Heritage line. The R 18 has the standard version and the Classic. The nineT line has a standard version, along with the Scrambler, Pure, and historically minded /5.


It’s straightforward in the Roadster line. They all have an R suffice, which tells you that it’s a naked upright sportbike.


  • RR: When you think of RR, think of Road Racing. These are the highest-performance BMW motorcycle.
  • RS: While the GS is off-road/sport, the RS is road/sport, including sport-touring when you add bags.


  • B: If you want a low-slung Bagger, look for the B designation
  • GTL: GTL is the touring line’s dresser, so GTL tells you it’s a Grand Touring Luxury motorcycle.
  • GT: Remove the luxury and add a bit of sport, and you have Grand Touring.
  • Grand America: The Grand America takes the Bagger concept and converts it to a dresser.
  • RT: It’s back to German for this designation—Reise-Tourer, which translates to travel-tourer. It’s the only boxer in the Tour lineup, and it functions as a sport-tourer. However, it’s not as sporty as the RS in the Sport line.

Once you learn everything in this story, you will be recognizing BMW model names intuitively.