There's no single definitive answer to what car has the *least* horsepower. Many cars, especially small, fuel-efficient city cars and some older models, have very low horsepower figures. The exact lowest would depend on the current model year and specific trim levels offered by various manufacturers. Many manufacturers also don't prominently advertise extremely low horsepower figures.
To find a car with very low horsepower, you'd need to research current specifications for various microcars and city vehicles from different countries.
