The NRG 900 is the only series of superbikes in Grand Theft Auto IV, and is available in two variants: The NRG 900F and the NRG 900RR. Depending of the version, the F variant has a similar front end to the early 2000's GSX-R750 models, while the RR variant is closely based on more recent GSX-R1000 models. The NRG 900 is mostly based on the Suzuki GSX-R series.
The name suggests a connection to the NRG-500 racing bike from Grand Theft Auto: San Andreas possibly that the NRG 900 is a modernized, commercial version of the NRG-500. The NRG 900 is a sport bike which inherits the general design and role previously filled by the PCJ-600 in the 3D Universe (considering that the HD era's PCJ-600 is now redesigned into a streetfighter, rather than a sport bike).
