A declining economy coupled with the soaring energy prices of the 1970s, American Motor Corporation (AMC) struggled in 1980. Their vehicle lineup wasn't able to keep pace with General Motors, Chrysler and Ford. And Japanese imports were now being produced domestically in highly efficient assembly plants.

Not able to secure loans from traditional sources, Renault provided funding to keep AMC going and eventually acquired more than 50% of the company by 1982. The company turned focus to its Jeep brand with down-sized versions of other models; the Wagoneer and Cherokee -- launched in 1983 -- created an entirely new sports utility vehicle class of cars.

Initially, these vehicles had a 2.5L inline-4 AMC engine or a GM-made 2.8L V6, both naturally aspirated with a carburetor. In 1987, Jeep and Renault designed an inline, 6-cylinder engine. Drawing from another Renault joint venture with aerospace company Bendix, they outfitted both the 2.5L and 4L engine with an electronic fuel injection system. Renault-Bendix was shortened to Renix.

When Chysler acquired Jeep in 1991, they replaced the engine management system with their own ECU. However, during just those four years of production, Jeep sold a combined 1.1 million vehicles with the Renix system.