Geographies of expertise in the dieselgate scandal: From a politics of accuracy to a politics of acceptability?

Drawing on semi‐structured interviews, this paper examines the geographies of environmental expertise underpinning the “dieselgate” scandal as it has played out at the EU level. It begins by mapping the scandal as a conflict between two distinct “knowledge space‐times.” The first of these – underpinned by official off‐the‐road vehicle emissions tests – links epistemic credibility to the ideal of experimental reproducibility. The second – underpinned by the “crowdsourcing” of publicly generated fuel economy measurements – links epistemic credibility to the ideals of empirical richness and diversity. The paper argues, however, that “expertise” in this controversy should not be understood exclusively as the attribute of knowledge produced according to particular spatial or temporal logics. Instead, the boundaries of credible expertise in this case are predetermined by an “anti‐political” ontology of vehicle emissions which presumes their status as a single, homogenous object of governance. Drawing on Barry's concept of “metrological regimes,” the paper therefore contends that the full political potential of dieselgate can only be unlocked by inventing new logics of counting and categorisation that might force us to think differently about how best to partition, label, measure, and ultimately govern the inherently messy practices from which individual acts of driving – and hence vehicle emissions – emerge in the first place.