This page contains some general info on Volkswagen’s Jetta line, it’s history, and some of the changes and modifications made to the Jetta series during it’s history.
Instead of rewriting all of this information I will cite the very thorough entry for Jetta found at Wikipedia.
A1 (1980 – 1984)
The first-generation Jetta appeared in the North American market in 1980, available as a two-door coupe and four-door sedan. Styling was penned at ItalDesign, by Giorgetto Giugiaro. A version of this model, known as the Volkswagen Fox, continued in production in South Africa until the late 1990s. In some markets such as in Mexico the A1 Jetta was known as the Volkswagen Atlantic.
Powering the base A1 Jetta and GL trim in 1980 was a standard 1.6 L four-cylinder producing 78 hp (57 kW) and 83 ft·lbf (113 N·m) torque. In 1981, the engine was upgraded to a 1.7 L producing 74 hp (54 kW) and 90 ft·lbf (121 N·m) torque. Additional engine choices were a diesel 1.6 L four making 50 hp (37 kW) and, in 1984 (the final year of the A1), a “GLI” high-performance version was offered, powered by the 1.8 L engine and close-ratio transmission from the Rabbit GTI, which made 90 hp (67 kW) and 105 ft·lbf (142 N·m) torque.
A2 (1985 – 1992)
The longest reigning Jetta of all time, the second-generation A2 proved to be a sales success for Volkswagen, outnumbering Golf sales two-to-one, and securing the title of best-selling European car in the US. It was also one of the first Volkswagen models produced in China. Like the A1 series, the A2s were offered as two-door coupes or four-door sedans; coupes were limited to the base, Wolfsburg and diesel trim levels. Major exterior changes throughout the series run include the elimination of the front-quarter windows in 1988, the addition of larger, body-colored bumper covers, and lower side skirts from 1990 to 1992, and several grille and side-cladding changes.
The base and GL trim levels were powered by a 1.8 L I4 rated at 100 hp (RV code digifant engine w/ single outlet manifold) (75 kW) and later 105 hp (PF code digifant engine w/ dual outlet manifold) (79 kW). There were three diesel engines offered in the A2 series, a 1.6 L naturally-aspirated diesel with 52 hp (39 kW), a 1.6 L 68 hp (51 kW) turbo diesel, and a 1.6 L diesel (the ECOdiesel) was sold for two model years, 1991 and 1992, it made 59 hp (43 kW) and 81 ft·lbf (109 N·m) of torque. The Carat was essentially a luxury trim without the performance upgrade of the GLI. For the A2 series, the GLI was powered by a 1.8 L four with 100 hp (75 kW), then a 1.8 L DOHC 16-valve that made 123 hp (92 kW) in 1987. But the GLI soon became a serious performance contender with the addition of the 2.0 L DOHC 16-valve four in 1990. The 2.0 L in the GLI and GTI 16v was powered by the CIS Motronic engine management system. It was rated at 134 hp (99 kW).
A3 (1991 – 1998)
Known in Europe as the Vento, the A3 was a refined evolution of the previous-generation Jetta. The Vento debuted in 1991 while the Jetta debuted in 1993. Hailed as the “Poor Man’s BMW”, it was designed in-house under Herbert Schafer. The third-generation series was criticized for its “boxy” design. Though only offered as a four-door sedan, the A3 spawned more trim levels than any other Jetta line. Exterior changes to the A3 through its production run were subtle, such as a new grille, body-colored rub strips, and different wheel covers.
The GL was the base trim while the GLS was the luxury trim with leather seats and power locks, windows, sunroof, etc. The Trek was a special trim that included a bike rack, a Trek bike, spoiler, rocker panel covers, alloy wheels, and in 1997, other accessories and options available for the top-of the line GLX, save for the VR6 engine. The K2 was a similar package, but in place of the bike was a K2 snowboard or a pair of K2 skis. The City was a utilitarian Jetta without a radio or air conditioning, while the 1994 Limited Edition and 1995 Celebration packages were value-priced GLs costing some $600 less than standard. The Jazz Edition was a GL with a 6-disc CD player standard. All were powered by a 2.0 L I4 making 115 hp (86 kW). The diesel engine once again made its comeback with VW’s revolutionary 1.9 L TDI (Turbo Direct Injection) 90 hp (67 kW) diesel engine and was offered as a separate trim level. By far, one of the most exciting trim levels was the GLX, replacing the GLI designation. Motivated by the renowned VR6 SOHC six-cylinder, the 172 hp (128 kW) powerplant was able to catapult the Jetta to 60 mph in 6.9 seconds, the fastest Jetta to date. For those who preferred the GLX’s looks, the GT and Wolfsburg Edition offered GLX accessories without the venerable VR6.
A4 (1998 – 2005)
Known as the Bora in Europe, the fourth-generation Jetta debuted in late 1998 after its larger sibling, the Passat, with which it shares many styling cues. The rounded shape and arched roofline serves as the new Volkswagen styling trademark, abandoning traditional sharp creases for curved corners. The A4 came in three different trim levels, and was also offered as a wagon. In some European markets, the station wagon version was marketed as a Golf (“Estate” in the UK and Ireland, “Break” in France) and had a Golf grille and headlights.
The GL was the base model, powered by a slightly revised 2.0 L 8-valve four based on the previous models, a 1.9 L TDI (Turbo Direct Injection turbo diesel), and from 2003 on by the turbocharged 1.8 L engine. The GLS was a step up, with options for leather seats and a sport package. This line offered all engine choices until 2003, when the VR6 choice was dropped. The GLX was the luxury model, with leather seats, wood grain trim, automatic climate control, rain-sensing windshield wipers, and other amenities. In 2003, the VR6 engine moved to a drive-by-wire 24-valve design rated at 200 hp (150 kW). It was available in the GLX and the new-for-2003 GLI model. The GLI offered sport suspension, six-speed manual transmission, and the 200 hp (150 kW) VR6. In 2004, the GLX model was dropped.
In 2004, Volkswagen offered the GLI in two versions; the ‘standard’ GLI and the limited edition 20th Anniversary Edition GLI. The Anniversary Edition offered a 180 hp 1.8 L inline-4, linked to a 6-speed manual transmission. The car received a stiffer and lower suspension, body kit (often refered to as Wide-Body), larger brakes, headlights and smoked taillights (which are actually not smoked only appear so), and 18″ (457 mm) BBS wheels equipped with low profile 40 series high-performance summer tires. VW also installed a stainless steel exhaust with a chrome tip. There were no options available. The GLI came equipped with ESP (Electronic Stability Program) to improve vehicle handling and safety in low-traction road conditions. The GLI was available in red, blue, silver-grey, and black. The interior was black with aluminum trim, including black upholstered Recaro bucket seats with red “GLI” lettering embroidered on the backrest (instead of the headrest), and a 200 Watt Monsoon 8-speaker stereo system with in-dash tape deck and CD player. The car could accelerate from 0 to 60 mph in 6.7 sec with a top speed of 146 mph.
Starting with the 2002 model year, all Jettas equipped with 1.8T engines, regardless of trim level, produced 180 horsepower (“AWP” engine code). This was a 10-horsepower improvement over the previous 170 hp 1.8T and was accomplished with a slightly larger turbocharger and other minor changes. The engine block was not changed.
A5 (2005 – present)
Built in Puebla, Mexico and exported to North America and Europe where the A5 is called again Jetta, is larger than the fourth generation, with more upscale styling and greater interior room. One major change is the introduction of the first independent rear suspension in a Jetta.
The base engine is a 2.5 L (2480 cc) I5 producing 110 kW (150 hp DIN) and 168 ft·lbf (228 N·m) of torque. This new 20-valve DOHC engine is based on the Lamborghini Gallardo‘s V10, sharing a similar head design and the same bore and stroke dimensions (82.5 x 92.8 mm). Replacing the venerable 1.8 T is a turbocharged 2.0 L 16-valve I4 rated at 147 kW (200 hp DIN). There is also a diesel powerplant, a 1.9 L TDI engine producing 74 kW (100 hp DIN) and 177 ft·lbf (250 N·m) of torque.
In North America, the A5 Jetta went on sale in March 2005, as a 2005 1/2 model, overlapping the final model year of the A4 Jetta. A GLI version was released as a 2006 model in North America in the summer of 2005. The new Jetta was designed by Walter de’Silva. 2005 sales of the New Jetta were dissappointing in the US. While critics embraced the overall vehicle, they claimed the styling was too Japanese (with similarities to the Toyota Corolla), and that it is too high-priced for the highly competetive compact car market.
Volkswagen announced the Jetta in Europe in late May 2005. The model range returns to using the Jetta name on the continent, rather than Bora or Vento. In other parts of the world, this model does retain both names, usually in cases where a previous mark is still sold. For example, in Mexico, the A4 is still sold as the Jetta, while the A5 is the Bora. In China, the A2 is still sold as the Jetta, while the A5 is sold as the Bora.