• Engines and motors reach a pseudo-steady state process at every second of vehicle operation. • Equivalent vehicle emission maps are constructed by testing the vehicle with a PEMS. • Fuel consumption and emissions were measured on motorcycles performing two driving cycles. • The obtained maps are unique regardless of the vehicle operational conditions. • The equivalent vehicle map isolates the external conditions on vehicle performance. • They can be used as an alternative to regulate low-cost vehicle technologies. This study aims to determine “equivalent vehicle maps” by testing the entire vehicle on-road or on a chassis dynamometer while monitoring its instantaneous fuel/energy consumption and tailpipe emissions at 1 Hz. This approach assumes that at every second of vehicle operation, the engine/motor reaches a pseudo-steady state, and that, for every mode of operation (engine-torque bin), the vehicle’s fuel consumption and emissions are unaffected by prior engine operating states. The dynamic time-event synchronization of variables measured at the engine with those at the tailpipe is crucial to this approach. The obtained maps of the vehicle’s energy consumption as a function of engine torque and RPM include the inefficiencies of the vehicle’s powertrain (engine, transmission, and final drive) and, therefore, differ from those reported by manufacturers, which are obtained by testing solely the engine on a test bench. To demonstrate this approach, four motorcycles were tested, reproducing two dissimilar driving cycles. Results confirmed that the obtained maps per driving cycle were similar (Similitude cosine > 0.9 for fuel consumption, > 0.9 for CO 2 , and > 0.8 for CO, NOx, and PM 2.5 ). The power of this approach is that it simplifies the energy and environmental characterization of vehicle technologies, enabling the accurate estimation of real-world emissions and fuel consumption of vehicles operating under normal conditions of use, including on non-flat terrain. Furthermore, this methodology allows environmental authorities to evaluate vehicle technologies under local operating conditions.
Castillo et al. (Fri,) studied this question.