SUVs are frequently referred to as "city 4x4s", as they are a compromise between an MPV and an off-road 4x4 vehicle.
But contrary to the primary vocation of 4x4s, which is to drive off-road over often rugged and steep terrain, SUVs, even when equipped with 4-wheel drive, are not suited to the most difficult terrain, as they lack, for example, differential locks, two axles to guide the front and rear wheels, two gearshift levers, and so on.