Weight a minute! Is the mass of passenger vehicles actually increasing? If so, is it driven by electrification, aspiration or bloat? And what are the impacts on energy use of vehicle size and mass?

Extended abstract 6-037-26

There has been much discussion recently regarding increases in car size and weight – driven by both 'SUV'isation of the fleet and electrification. This study draws on over a decade of EU vehicle type approval data to examine patterns in model availability and registration across Europe.  This presentation will predominantly focus on the energy impacts of these changes. New registrations are particularly important in the energy transition, as the cars we buy today may well be still on the road in 2050 and beyond.

The study reviews recent work on vehicle safety and public space. The presentation will consider key historical developments in vehicle safety that have contributed to size increases – such as changes in chassis construction and the introduction of side airbags, as well as possible evidence of rapid changes in electrification permitting ‘lightweighting’.  It will also examine whether the term 'SUV' has any substantial meaning beyond styling, whether premium brands show a significant bias towards larger vehicles, and what national differences in vehicle preferences might reveal about cultural and social factors involved.

Alongside vehicle mass, axle width and wheelbase, the type approval data provides CO₂ emissions for internal combustion engines and, for electric vehicles, electricity consumption and range. These have been used to undertake an analysis of the relationship between vehicle size and energy consumption.  For the UK, where mileage data for individual vehicles is calculable, estimates have been made of annual mileage differentials between larger and smaller vehicles, ensuring the impacts of actual usage are considered.

The sheer diversity between countries apparent in the data indicates that the ongoing transition is as much social as technological.

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