The new Land Rover is easily the most technically sophisticated of the three, with an aluminum unit body and fully independent suspension (the others have solid rear axles). At its 1948 introduction, the Land Rover was meant to be a work vehicle. In 2016, the lineal descendant of that first Land Rover, renamed Defender in 1990, went out of production, ending a 68-year run. Land Rover has just begun delivering the Defender to Americans in its larger four-door guise, known as the 110. Joe Eberhardt, the chief executive of Jaguar Land Rover North America, is sanguine about the Defender’s prospects, while acknowledging the appeal of the two American rivals.