In this study the performance of a monofuel compressed natural gas articulated truck was investigated under real-world conditions. To analyze the CNG vehicle due to fuel consumption and exhaust emissions a representative road-test route was conducted, including sections with significantly different driving conditions. Moreover, driving tests on freeway under higher load were carried out.As experimental equipment, a new ultra compact on-board system measured the in-car exhaust mass emissions in real time. Every second, a full dataset of CO₂, CO, HC and NOx emission rates was provided. The real-world emission measurements are based on a modal analysis of the emission concentrations in the tailpipe of the vehicle. The exhaust gas mass flow is calculated from the air mass flow and the gas components with a real-time reaction model. In combination with the vehicle speed, the emission rates in g/s are then calculated in gram per kilometer. Furthermore, the fuel consumption in g/s or kg/100 km is calculated with the carbon balance method according to the EU Commission directive 1999/100/EC.The gained distance related emissions and the derived mean values are based on the several thousand individual datasets measured at the drive tests. In order to link the measured exhaust emission data with geographical information of the road-test route a GPS tracking was implemented as well.Additionally, the application of new calculation and experimental methods in this investigation allowed developing characteristic maps of the CNG powertrain based on the real-world measurement data.