The objective of the Consumers, Vehicles and Energy Integration project is to inform UK Government and European policy and to help shape energy and automotive industry products, propositions and investment strategies. Additionally, it aims to develop an integrated set of analytical tools that models future market scenarios in order to test the impact of future policy, industry and societal choices.The project is made up of two stages:Stage 1 aims to characterize market and policy frameworks, business propositions, and the integrated vehicle and energy infrastructure system and technologies best suited to enabling a cost-effective UK energy system for low- carbon vehicles, using the amalgamated analytical toolset.Stage 2 aims to fill knowledge gaps and validate assumptions from Stage 1 through scientifically robust research, including real world trials with private vehicle consumers and case studies with business fleets. A mainstream consumer uptake trial will be carried out to measure attitudes to PiVs after direct experience of them, and consumer charging trials will measure mainstream consumer PiV charging behaviours and responses to managed charging options.This report represents Deliverable D6.1, Fleet Study Report. Little is known about the attitudes of Light Duty fleet operators to Plug-in Vehicle (PiV) adoption or PiV use; published research has been very limited. This report is intended to inform appropriate sensitivity analyses to be conducted in the Modelling and System Analysis work package (WP7), based on in-depth qualitative insights into the processes influencing vehicle choice, and likely charging profiles, in those categories of Fleets where PiV uptake could potentially have most impact on the wider energy system.The reportsummarises the methods employed and the findings from five individual case studies, and provides: a synthesis of insights gained across the case studies considered collectively; answers to the research questions defined in the Fleet Study design; and evidence-based conclusions from the Fleet Study with regard to how the findings have advanced understanding of Fleets, their potential impact on the energy system and integration into it (based on qualitative data), and therefore what the new state-of-the-art understanding of this area is.