10. Mazda R100
Mazda may have not been the first to build a passenger vehicle with a rotary engine, but the manufacturer is best known for these internal-triangle engines. The R100 was part of Mazda’s rotary engine expansion efforts and was the first vehicle exported to the USA featuring this motor. Featuring 2 rotors that totaled 982 cc of displacement, the engine produced 100 hp, thus the name R100 (R standing for rotary).