Le Mans, the 1st to 4th placed cars were Jaguar D-Type entries using a Lucas fuel injection system. Also in 1957, General Motors introduced the Rochester Ramjet option, consisting of a fuel injection system for the V8 engine in the Chevrolet Corvette. During the 1960s, fuel injection systems were also produced by Hilborn, SPICA and Kugelfischer. Up until this time, the fuel injection systems had used a mechanical control system. In 1957, the American Bendix Electrojector system was introduced, which used analogue electronics for the control system. The Electrojector was intended to be available for the Rambler Rebel mid-size car, however reliability problems meant that the fuel injection option was not offered. In 1958, the Chrysler 300D, DeSoto Adventurer, Dodge D-500 and Plymouth Fury offered the Electrojector system, becoming the first cars known to use an electronic fuel injection (EFI) system. The Electrojector patents were subsequently sold to Bosch, who developed the Electrojector into the Bosch D-Jetronic. The D-Jetronic was produced from 1967-1976 and first used on the VW 1600TL/E. The system was a speed/density system, using engine speed and intake manifold air density to calculate the amount of fuel to be injected. In 1974, Bosch introduced the K-Jetronic system, which used a continuous flow of fuel from the injectors (rather than the pulsed flow of the D-Jetronic system). K-Jetronic was a mechanical injection system, using a plunger actuated by the intake manifold pressure which then controlled the fuel flow to the injectors. Also in 1974, Bosch introduced the L-Jetronic system, a pulsed flow system which used an air flow meter to calculate the amount of fuel required. L-Jetronic was widely adopted on European cars during the 1970s and 1980s. As a system that uses electronically-controlled fuel injectors which open and close to control the amount of fuel entering the engine, the L-Jetronic system uses the same basic principles as modern electronic fuel injection (EFI) systems. 1980s – present: digital electronics and common-rail injection Prior to 1979, the electronics in fuel injection systems used analogue electronics for the control system. The Bosch Motronic multi-point fuel injection system (also amongst the first systems where the ignition system is controlled by the same device as the fuel injection system) was the first mass-produced system to use digital electronics. The Ford EEC-III single-point fuel injection system, introduced in 1980, was another early digital fuel injection system. These and other electronic manifold injection systems