Climate protection goals in transportation can only be achieved with a worldwide change in mobility behavior that is supported by technological progress and changes in vehicle concepts. One contribution to reducing greenhouse gas emissions may be using small and light electric vehicles (LEVs) instead of cars. LEVs have a favorable ratio of vehicle weight to payload and the efficiency of electric drives contributes to environmental sustainability. As with full-sized electrically powered cars, emissions from combustion processes are eliminated. Going beyond that, the traction batteries in LEVs can be considerably smaller, thereby reducing the consumption of critical raw materials and lowering production-related greenhouse gas emissions. Against this background, we present the results of a study which aimed to determine what proportion of current passenger car trips in Germany could, in theoretical terms, be covered by LEVs. Our estimation of the substitution potential of LEVs for car trips is based on the 2017 Mobility in Germany (MiD) survey, a national household travel survey (NHTS) containing the data of 960,619 trips. Many different types of vehicles, ranging from e-scooters, cargo bikes, and pedelecs to three- and four-wheeled light electric vehicles, are considered. The results show that up to 76% of car trips and 50% of car mileage could theoretically be substituted by LEVs. The results are further analyzed to determine for which trip purposes and age groups the greatest substitution potential exists. Based on the results, we discuss ways for supporting the realization of this potential as well as factors that determine whether the theoretically calculated potential can be realized.