Abstract Purpose Environmental assessments of efforts to reduce vehicle fuel consumption require scientifically sound and robust fuel consumption models. The purpose of this paper is to introduce a novel method and model for calculating fuel consumption. Method This paper presents a method of powertrain modeling that is based on driving and powertrain physics, such as a net force approach to calculate force demand at the tire patch, and the use of engine maps to model engine efficiency. Results The presented method provides parsimonious open-source powertrain modeling to the environmental assessment community, thus an alternative to existing approaches. The modeling results are in agreement with existing values, while the modeling method is more flexible and avoids unnecessary approximations. Conclusions Existing fuel consumption modeling consists of very detailed and complex powertrain simulation models, typically not available for environmental vehicle assessments, or streamlined equation-based methods that use a mix of physical laws, engineering approximations, and sometimes accounting principles. The presented modeling method and open-source model provide a valuable alternative.

Abstract Purpose Environmental assessments of electric vehicles (EV) require scientifically sound and robust fuel consumption models. The purpose of this paper is to introduce a novel method and model for calculating energy demand of battery electric (BEV) and series plug-in hybrid electric (PHEV) vehicles. Methods This paper presents an open-source simulation model for BEV and series PHEV powertrains. It is based on driving and powertrain physics, such as a net force approach to calculate force demand at the tire patch, and the use of motor maps to model motor efficiency. The modeling approach is well suited to include important EV powertrain aspects, such as regenerative braking and battery charging and discharging losses. Results The presented method provides parsimonious open-source EV powertrain modeling to the environmental assessment community. It enables the calculation of vehicle energy demand (in MJ/100 km) and so-called energy reduction values (in MJ/100 km and 100 kg vehicle mass reduction) that are specific to each EV configuration and design change. Conclusions The presented EV powertrain model complements the ICV powertrain model introduced in part 1 of this paper series. It uses the same modeling methods as the ICV model, which gives it the same modeling advantages, and also facilitates environmental comparisons across powertrain types.