Testing energy efficiency and driving range of electric vehicles in relation to gear selection

Electric vehicles (EVs) have the potential to be operated using a clean, renewable energy source. However, a major limitation is their relatively short vehicle driving range and the associated driver 'range anxiety'. This research investigates the effect of gearing on energy consumption and driving range efficiency on an EV-converted Ford Focus using a chassis dynamometer in a controlled test environment in accordance with international standards. Two designs of the Ford Focus were used in the tests; one with an automatic gear drive, and the other with a manual gear drive. The electricity consumption of the two cars driving under different gearing configurations was measured under identical drive cycles. The vehicle range tests showed that measuring energy consumption on just two consecutive drive cycles on a calibrated chassis dynamometer will lead to a small overestimation of the energy consumption due to a 'cold' drive train. The results also suggest greater attention needs to be paid to EV battery charger efficiency, particularly in terms of standby energy consumption, which can increase the total energy required for EV owners markedly.