a few months later mildly restyled, further set apart from the 1.6 by a new grille with a wider central shield and horizontal chrome bars. Engines in both models were Alfa Romeo Twin Cams, with two overhead camshafts, 8-valves and two double-barrel carburettors. Two years later the 1.6 was upgraded to the exterior and interior features of the 1.8. In 1977 a 2.0-litre model was added. Launched at the March Geneva Motor Show, the Alfetta 2000 replaced the outgoing Alfa Romeo 2000. This range-topping Alfetta was longer than the others, owing to a redesigned front end with square headlights and to larger bumpers with polyurethane inserts; the rectangular tail light clusters and C-pillar vents were revised, as were the dash, steering wheel and upholstery. Just a year later, in July 1978, the two-litre model was updated becoming the Alfetta 2000 L. Engine output rose from to ; with revised upholstery and simulated wood dash. The Alfetta 2000 was marketed as the Alfa Romeo Sport Sedan in the United States, where "Alfetta" had less recognition than Europe. The 2000 received fuel injection in 1979. A turbodiesel version was introduced in late 1979, the Alfetta Turbo D, whose engine was supplied by VM Motori. Apart from a boot lid badge, the Turbo D was equipped and finished like the top-of-the-line 2000 L both outside and inside. Therefore, it received a tachometer, but no standard power steering, despite an additional carried by the front axle. The turbodiesel, a first on an Alfa Romeo's passenger car, was of 2.0 litres and produced . The Alfetta Turbo D was marketed mostly in Italy and in France, as well as a few other continental European markets with a favorable tax structure. In 1981 Alfa Romeo developed in collaboration with the University of Genoa a semi-experimental Alfetta version, fitted with a modular variable displacement engine and an electronic engine control unit. Called Alfetta CEM (Controllo Elettronico del Motore, or Electronic Engine Management), it was shown at the Frankfurt Motor Show. The 2.0-litre modular engine featured fuel injection and ignition systems governed by an engine control unit, which could shut off two of four cylinders as needed in order to reduce fuel consumption. An initial batch of ten examples were assigned to taxi drivers in Milan, to verify operation and performance in real-world situations. According to Alfa Romeo during these tests cylinder deactivation was found to reduce fuel