The B3 obtained a major facelift for the 1992 model year in 1991. It was from then on known internally as the B4 (or Typ 8C). Changes from the B3 included a longer wheelbase, a fully redesigned fuel tank and rear axle to enable the use of folding seats, 15″ roadwheels with more prominent wheel arches, redesigned and painted rear and front bumpers, as well as higher-quality materials for the interior. The front grille was merged with the bonnet and given a bolder look.
The B4 also marked the beginning of Audi’s move into the German luxury mid-sized vehicle segment, which until then was clearly dominated by Mercedes-Benz and BMW. On the European market, and in Germany in particular, the B4 and its variants were highly successful and popular.
In Europe, the 90 name was discontinued, and all saloons were badged as 80, regardless of which engine they had. Audi of America went the opposite direction, and began selling the saloon as the 90. B4s for the American market typically offered more luxury even in the standard version, such as automatic transmission,cruise control, air conditioning and leather seats, all of which were usually optional at additional cost (or standard) on European models.
Because the United States does not recognise the international ECE Regulations on auto safety components and constructions, but rather maintains its own Federal Motor Vehicle Safety Standards, the front of the B4 had to be specially redesigned for vehicles sold in North America. The front and bumper had to be designed to accommodate impact energy absorbers not required outside North America. Instead of the dual-reflector headlamps, a single-reflector design was used inboard of an amber combination turn signal, parking, and side marker lamp and reflector wrapping around the corner, and fog lamps smaller than the rest-of-world items were placed the corners of the bumper air duct.
European market cars were now available with a selection of inline four-cylinder engines, as well as the familiar in-line five, and two different new V6 engines (2.6 and 2.8); the later 2.8 V6 was the only engine available for vehicles sold in North America. As another first, Audi introduced a new high-torque, direct-injection, turbocharged diesel engine, the 66 kilowatts (90 PS; 89 bhp) 1.9 TDI (Turbocharged Direct Injection). The standard 1.8-litre petrol engine of the B3 was discontinued; a two-litre, 66 kW (90 PS; 89 bhp), 4-cylinder petrol engine, a variation of the previously known 85 kW (116 PS; 114 bhp) 2.0 E engine, was now available for the base model.
Together with the saloon, Audi produced a B4-based estate, the Audi 80 Avant, and a convertible, the Audi Cabriolet, which was largely based on the B3 Coupé. This meant that Audi now had saloon, coupé, cabriolet, and estate variants of the 80 available to European customers. For the North American market, however, Audi only sold coupés during the 1990 and 1991 model years, and the station wagon was never officially available. The Cabriolet was the company’s first soft-top since the Auto Union 1000 Sp of 1959. Initially available with the 2.8-litre V6, and then 2.6-litre V6 were offered later. Heavily engineered to retain the structural strength of the Coupé (with which it shared sports suspension), its screen was reinforced to preclude the need for a roll bar.
As of the 1994 model year, a limited edition model, known as Europa, was introduced on the European market. It could be ordered both as a saloon and an Avant. It was factory-equipped with power mirrors, alloy wheels, rear seat headrests, an airbag steering wheel, and offered a choice between power sunroof orair conditioning. It came in five different special colours. For “regular” 1994 B4 saloons and Avants, standard features as well as options available were stepped up too, including an airbag steering wheel and redesigned door liners (standard), and passenger airbags and a built-in engine immobiliser (optional).
The 80-series was effectively replaced by the new Audi A4 in 1996, a variant of the 1996 Volkswagen Passat. By that time it was feeling very dated in comparison with more modern rivals like the E36 BMW 3 Series. Production ceased at a time when prestige European manufacturers were making the transition of older executive saloons to newer models based on newer platforms in the compact executive car market.
The B4 saloon was discontinued at the end of the 1994 model year (although a number of European vehicles are known to have been first registered as late as early 1995; in North America, sales continued into 1995 as well). Avant and Coupé followed suit in 1995/96. The Cabriolet, however, was carried on until 2000. As of the 1998 model year, it underwent a few minor yet visible touch-ups in its European version, such as gently redesigned bumpers and instrument clusters, projection lens headlights and more options available. In addition to this facelift, a special edition was introduced for the European market under the name Sunline. Among other specs, it was equipped with all leather interior, air conditioning, 16-inch alloy wheels, a power soft-top and a leather steering wheel.
Both the Coupé and the Cabriolet were effectively replaced by the first-generation Audi TT coupé and roadster, sold between 1998 and 2006. The B4 platform saloon was replaced by the Audi A4 for the 1995 model year (1996 in North America), followed by a new A4 Avant later in 1996. A mid-sized convertible was not available again until 2002, when the A4 Cabriolet was introduced. Audi has released a new mid-sized coupé for the 2008 model year, which is now known as the Audi A5.