Tata Motors has become India's largest automobile firm, surpassing Maruti Suzuki with an m-cap of $48 billion, as per CNBC-TV18. The world's largest automobile firm is Tesla, with an m-cap of $704 billion, followed by Toyota ($299-billion m-cap) and China's BYD ($97-billion m-cap). The other biggest automobile firms include Mercedes-Benz, Ferrari, Porsche, BMW, Volkswagen, Stellantis and Honda.