Performance Evaluation of Passenger Car, Fuel And Powerplant Options

Road transport needs de-carbonising actions, but no single solution can solve this challenge. Therefore, multiple technologies must be entertained to find the best-suited alternatives for each given set of boundary conditions. Engine downsizing, dieselization and hybridization contribute to fuel efficiency. Renewable energy can be introduced either through biofuels or electricity from renewable sources to further reduce CO2 emissions. There are numerous individual vehicle types, makes and models, thus the evaluation of future options is challenging. This project aims to deliver first-hand primary data for this kind of evaluations, and improve possibilities to make right-kind of choices among available options.This study demonstrates the differences in efficiency arising from fuel, engine type and size. The core of the evaluation consists of benchmarking a set of passenger cars (“vehicle platforms”) of such make and model that offer multiple choices for engine, i.e. gasoline, flex-fuel (E85), diesel, compressed natural gas (CNG), liquefied petroleum gas (LPG), hybrid or EV variations. In addition, the project also demonstrates the differences in efficiency arising from engine type and size. Chassis dynamometer testing provides data on the end-use performance of alternative vehicles. The upstream well-to-tank data for various fuel options is collected by a literature survey.Findings of this study show that while the choice of vehicles engine type and size determines much of the energy consumption of the vehicle, fuel properties still have a major effect on both energy efficiency and tailpipe emissions. Battery electric vehicle was found to be the most energy efficient alternative on all driving situations while the high powered gasoline engine was the worst. The tank-to-wheel (TTW) energy consumption of this upper middle class vehicle was roughly 2.3 to 4.7 times higher on high power gasoline engine than on battery electric vehicle. The maximum power of the engine and the engine type has also an effect to the energy consumption of the vehicle. The powerful gasoline engine consumed some 23 % to 33 % more energy than the moderately powered version. The results of the diesel vehicles support this finding, although the energy efficiency difference between powerful and moderately powered diesel versions was smaller. However, well-to-tank (WTT) properties of the fuel have a significant influence to well-to-wheel (WTW) results, which needs to be considered. The TTW CO2 emissions difference between the two extremes was roughly 1.6 to 1, while the WTW CO2 emissions difference between the two extremes was some 4 to 1.