I don't think Yamaha Motor is producing any large trucks. They do a lot of things but mostly motorcycles, atv, boat engine, even car engines but not the whole car.
Also, you should note that Yamaha Corporation, the musical instrument maker and Yamaha Motor are now 2 distinct independent companies, even if were originally part of the same group.
Also, you should note that Yamaha Corporation, the musical instrument maker and Yamaha Motor are now 2 distinct independent companies, even if were originally part of the same group.