British refiners initially used "motor spirit" like a generic title to the automotive fuel and "aviation spirit" for aviation gasoline. When Carless was denied a trademark on "petrol" inside the 1930s, its rivals switched to the more popular title "petrol". Nonetheless, "motor spirit" had previously made its way into regulations https://jet-fuel88761.illawiki.com/666206/not_known_details_about_gasoline_alley_harley