Originally, up until Operation Overdrive (Toyline), all Zords and Megazords had been Bandai Japan Deluxe Megazords releases. With Overdrive, a new Transforming Megazords concept was born, wherein Zords were produced with the aim to lower production cost and retail price. The results were hollower, less dense plastic Zords. The trend continued up til RPM (Toyline). It was also with RPM that the term "Zord Vehicles" was coined. However, these zords were literally zords that transformed into vehicles- cars.