The word "loaner" refers to something that is borrowed or temporarily given to someone, usually without payment, to be used until they return it. Full definition
Our facility is state of the art and features premium amenities like an upscale customer lounge along with free loaner cars for service customers. (toyotaofboerne.com)
WE HAVE ONE OF THE LARGEST FLEETS OF FREE LOANER CARS. (dealerrater.com)