The emission benefits of shifting towards battery electric vehicles have so far been hampered by a trend towards sports utility vehicles (SUVs). This study assesses the current and future emissions from SUVs and their potential impact on public health and climate targets. We modelled five scenarios of varying SUV sales and electrification rates, and projected associated carbon dioxide (CO2) and nitrogen oxide (NOx) emissions. Multiple linear regression was used to determine the relationship between vehicle characteristics and emissions. Cumulative CO2 emissions were valued using the social cost of carbon approach. Life table analyses were used to project and value life years saved from NOx emission reductions. Larger SUVs were disproportionately high emitters of CO2 and NOx. Replacing these with small SUVs achieved significant benefits, saving 702 MtCO2e by 2050 and 1.8 million life years from NO2 reductions. The largest benefits were achieved when combined with electrification, saving 1181 MtCO2e and gaining 3.7 million life years, with a societal value in the range of GBP 10-100s billion(s). Downsizing SUVs could be associated with major public health benefits from reduced CO2 and NOx emissions, in addition to the benefits of electrification. This could be achieved by demand-side mass-based vehicle taxation and supply-side changes to regulations, by tying emission limits to a vehicle's footprint rather than its mass.