Can modified components make cars greener? A life cycle assessment

Abstract

The goal of this study is to evaluate which improvements to car components can most reduce its environmental impacts, narrowing the field to only those currently available on the market. The strategy of the material substitution is the more investigated together with mass reduction, even if the study does not ignore marginally shape optimization, controls, and production processes. Another goal is to discriminate the environmental benefits according to the size of the car and power supply, i.e., gasoline, hybrid and electric.To ensure the reliability and the reproducibility of the results, the study was conducted using the Life Cycle Assessment (LCA) methodology, following the international standards ISO 14040/44, limited to the determination of CO2 eq. Each considered datum was extracted from scientific papers and used within a rigorous structured methodology to calculate the environmental impacts for all the types of car. The functional unit was defined to refer the environmental benefits arising from each improvement of the components to the impacts of the car life cycle normalized for a distance travelled of 100 km in a typical European route.Overall, a reduction in overall car impacts between 7% and 14% was determined by combining all the best alternatives for each analysed component. The major advantage was guaranteed to internal combustion cars and minor to electric cars, while in terms of size, small car benefitted the most. Frame improvement alone provided 51% of the total impact reduction, followed at a distance by that on the bodywork.In conclusion, the study showed how the followed approach can be useful to combine a large amount of different and heterogeneous data while extracting general considerations for automotive eco-design. The structural lightning achieved through material substitution has been fundamental to reduce fuel and energy consumption, and therefore the impacts of the use phase. However, the moderate lightning ensured by aluminium is better than the larger one of carbon fiber and magnesium, whose greater impacts in material extraction, manufacturing, and end-of-life compromise their most sustainable use phase. A further investigation should be deserved to increase control over vehicle condition and driving patterns which resulted valuable options.