In an era where climate change dominates global discourse, Felix Leach and Nick Molden dive deep into the complexity of vehicle emissions in their groundbreaking new book. Building on the insights from Felix's previous work, Racing Toward Zero, this new release confronts the bewildering landscape of automotive pollution with a clear, rigorous approach: what one piece of information can best describe the environmental impact of cars? Our digital age bombards us with information, yet meaningful understanding often eludes us, particularly when it comes to climate issues like road vehicle emissions. As simple solutions to such a complex problem remain elusive, Leach and Molden advocate for a sophisticated, yet accessible perspective. They propose a radical simplification of how we consider the environmental impact of cars and explore the multifaceted impacts of various vehicle powertrains, pushing beyond CO2 emissions to address broader environmental and societal concerns.