The first TDI was a huge success right from the start. When installed in the third-generation Audi 100, the five-cylinder engine’s 2,461 cc displacement achieved 88 kW (120 hp) and 265 Nm (195.45 lb-ft) of torque, the latter at 2,250 rpm. A distributor-type injection pump sprayed the fuel into the combustion chambers.
A pioneering achievement: Top speed of nearly 200 km/h (124 mph), fuel consumption of 5.7 l/100 km (41.27 US mpg)
As the engine went into production in the Audi 100 Avant late in 1989, its muscular power marked the dawning of a new era. At that time, diesel engines were considered economical and durable but rather dull performers. However, with a top speed of nearly 200 km/h (124 mph), the Audi 100 2.5 TDI propelled its way into the ranks of fast touring sedans, also featuring enormous acceleration from zero and amazing fuel economy of 5.7 liters of diesel fuel/100 km (41.27 US mpg) – established in line with the valid standards at the time. What’s more, the car’s travel range between refills was very generous.
In the midsize class too, TDI engines from Audi began to triumph. Starting in 1991, the Audi 80 was powered by a four-cylinder, 1.9-liter diesel unit that delivered 66 kW (90 hp) and 182 Nm (134.24 lb-ft). Four years later, an upgraded version with 81 kW (110 hp) was added. The increase in power was mainly due to the use of a new turbocharger with adjustable guide blades on the exhaust side: The so-called VTG charger with variable turbine geometry enabled torque to be boosted smoothly and promptly, even from very low engine speeds.
In 1993, the brand with the four rings converted its entire diesel program to TDI engines, and then in 1994 Audi took the next step: The five-cylinder unit was upgraded to 103 kW (140 hp). A six-speed transmission became the production model, and for the first time the TDI was combined with permanent all-wheel drive – in the first TDI quattro. With 290 Nm (213.89 lb-ft) of torque at 1,900 rpm, 208 km/h (129.25 mph) top speed and 9.9 seconds for the standard acceleration test from standstill, this car almost instantly became a sensation. The TV spot with the question “Where’s the tank?” made it legendary: The A6 TDI covered a distance of up to 1,300 kilometers (808 miles) on a single tank of fuel.
1997: The first V6 TDI in a passenger car
In 1997 Audi yet again initiated a revolution – with the debut of the world’s first V6 TDI in a passenger car. With its four-valve cylinder head, another innovation, this 2.5-liter power unit delivered up to 110 kW (150 hp) and 310 Nm (228.64 lb-ft) of torque. Two years later this was followed by the first V8 TDI from Audi. Installed in the A8, this too introduced a groundbreaking technology – common rail injection. The 3.3-liter unit delivered 165 kW (224 hp) and produced 480 Nm (354.03 lb-ft) of torque. Its 242 km/h (150.37 mph) top speed and quiet operation further contributed to the pleasure of driving a TDI car.
Another important new solution was developed for the four-cylinder engine. In 2000, a new high-pressure injection system, whose integrated pump/nozzle elements generated 2,050 bar of pressure, boosted the output to 85 kW (115 hp) and later to 96 kW (130 hp).
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| Audi 80 TDI (1992) |
A pioneering achievement: Top speed of nearly 200 km/h (124 mph), fuel consumption of 5.7 l/100 km (41.27 US mpg)
As the engine went into production in the Audi 100 Avant late in 1989, its muscular power marked the dawning of a new era. At that time, diesel engines were considered economical and durable but rather dull performers. However, with a top speed of nearly 200 km/h (124 mph), the Audi 100 2.5 TDI propelled its way into the ranks of fast touring sedans, also featuring enormous acceleration from zero and amazing fuel economy of 5.7 liters of diesel fuel/100 km (41.27 US mpg) – established in line with the valid standards at the time. What’s more, the car’s travel range between refills was very generous.
In the midsize class too, TDI engines from Audi began to triumph. Starting in 1991, the Audi 80 was powered by a four-cylinder, 1.9-liter diesel unit that delivered 66 kW (90 hp) and 182 Nm (134.24 lb-ft). Four years later, an upgraded version with 81 kW (110 hp) was added. The increase in power was mainly due to the use of a new turbocharger with adjustable guide blades on the exhaust side: The so-called VTG charger with variable turbine geometry enabled torque to be boosted smoothly and promptly, even from very low engine speeds.
In 1993, the brand with the four rings converted its entire diesel program to TDI engines, and then in 1994 Audi took the next step: The five-cylinder unit was upgraded to 103 kW (140 hp). A six-speed transmission became the production model, and for the first time the TDI was combined with permanent all-wheel drive – in the first TDI quattro. With 290 Nm (213.89 lb-ft) of torque at 1,900 rpm, 208 km/h (129.25 mph) top speed and 9.9 seconds for the standard acceleration test from standstill, this car almost instantly became a sensation. The TV spot with the question “Where’s the tank?” made it legendary: The A6 TDI covered a distance of up to 1,300 kilometers (808 miles) on a single tank of fuel.
1997: The first V6 TDI in a passenger car
In 1997 Audi yet again initiated a revolution – with the debut of the world’s first V6 TDI in a passenger car. With its four-valve cylinder head, another innovation, this 2.5-liter power unit delivered up to 110 kW (150 hp) and 310 Nm (228.64 lb-ft) of torque. Two years later this was followed by the first V8 TDI from Audi. Installed in the A8, this too introduced a groundbreaking technology – common rail injection. The 3.3-liter unit delivered 165 kW (224 hp) and produced 480 Nm (354.03 lb-ft) of torque. Its 242 km/h (150.37 mph) top speed and quiet operation further contributed to the pleasure of driving a TDI car.
Another important new solution was developed for the four-cylinder engine. In 2000, a new high-pressure injection system, whose integrated pump/nozzle elements generated 2,050 bar of pressure, boosted the output to 85 kW (115 hp) and later to 96 kW (130 hp).