Initially created as a military-specific car, the Geländewagen, also known as the G-Wagen and G-Class, is an SUV produced by Mercedes-Benz. A civilian version of the military G-Wagen was introduced for the 1980 model year, and since then has been produced in three generations: the first generation is the W460. Two generations were available at the same time: The W463 (Pre-Facelift) more consumer oriented and the W461, built specifically for military, public authorities and non-governmental organisations. The fourth generation is the W463 (Post-Facelift). The G-Class is one of Mercedes-Benz's longest running models, second only to the Unimog. Over the course of its production, the G-Wagen has featured numerous engines and configurations, including the outlandish G63 AMG 6x6.