By 1962, the output of the gasoline JH4 engine had crept up to . By the time of the introduction of the longer J20 in 1960, a six-seater like the J10, but with a differently configurated (more permanent) front windshield, as well as available metal doors, Mitsubishi had also added small diagonal skirts to the leading edge of the Jeep's front fenders. This remained the last change to the sheetmetal up front until the end of Mitsubishi Jeep production in 1998.