The newest line of BMW motorcycle
, nicknamed thus because they are oil-cooled, in contrast to the venerable air-cooled "R" series ("Airheads"
Airheads are fuel-injected, oil-cooled, have a horizontally-opposed twin-cylinder motor with four overhead valves per cylinder, unique Telelever front and Paralever rear suspension, and shaft drive.
The first oilhead, the R1100RS, was introduced in 1993, after which time BMW AG gradually phased out the airheads.
Oilhead models include: