The concept studies date from 2005 to the present. TDI engines with four, six, eight, ten and even twelve cylinders were used.
2007: Audi Q7 coastline
368 kW (500 hp), 1,000 Nm (737.6 lb-ft) of torque: The Q7 V12 TDI show car that Audi presented at the Detroit Auto Show in January 2007 was the herald of the production model launched in 2008. Its performance catapulted the concept SUV into the sports car league. The standard sprint took just 5.5 seconds, and acceleration did not stop until reaching an electronically-governed top speed of 250 km/h (155.3 mph).
The technology of the six-liter TDI corresponded to that of the production model. The common rail system with piezo injectors produced injection pressures of up to 2,000 bar. Both VGT turbochargers generated up to 1.6 bar of relative boost pressure. The crankcase was cast from vermicular graphite, and the cylinder banks were arranged at an angle of 60 degrees from one another. The V12 diesel from Audi also impressed with its incredible smoothness.
2008: Audi R8 V12 concept and the R8 TDI Le Mans
In early 2008, Audi presented the Audi R8 V12 TDI concept in Detroit. A few weeks later, the structurally identical R8 TDI Le Mans was at the Geneva Motor Show. Both studies referenced the victories that Audi scored at the 24-hour race with the R10 TDI in 2006 and 2007.
The show car features a six-liter V12 TDI similar to that in the race car. The mid-mounted engine sat directly behind the driver and passenger. The storage space for a golf bag normally found in the Audi R8 was eliminated. 368 kW (500 hp), 1,000 Nm (737.6 lb-ft) of torque – the latter at 1,750 rpm – accelerated the two-seater from 0 to 100 km/h (62.1 mph) in 4.2 seconds and beyond to a top speed of more than 300 km/h (186.4 mph). Fuel consumption was computed at less than ten liters per 100 kilometers (23.5 US mpg).
2008: Audi A3 TDI clubsport quattro
The Audi A3 TDI clubsport quattro was first presented in May 2008. It put out 165 kW (224 hp) and produced 450 Nm (331.9 lb-ft) of torque at 1,750 rpm. The show car sprinted from zero to 100 km/h (62.1 mph) in 6.6 seconds and reached a top speed of 240 km/h (149.1 mph).
The specific values for the two-liter diesel were 83.8 kW (113.8 hp) and 228.7 Nm (168.7 lb-ft) of torque per liter of displacement. An enlarged VTG turbocharger pressed the air into the combustion chambers; the common rail system injected the fuel under a pressure of 1,800 bar. Switchable resonance chambers in the tailpipes of the exhaust system gave the 2.0 TDI a full sound.
2010: Audi e-tron Spyder
The Audi e-tron Spyder, one of the stars of the 2010 Paris Motor Show, was an open two-seater measuring a good four meters (14.1 ft) in length. It had an aluminum structure in an Audi Space Frame design, an outer skin of carbon fiber-reinforced polymer (CFRP) and a plug-in hybrid drive.
A three-liter TDI with twin turbochargers drove the rear wheels with 221 kW (300 hp) and 650 Nm (479.4 lb-ft). Two electric motors with 64 kW and 352 Nm (259.6 lb-ft) powered the front wheels. They could be individually controlled, thus enabling intelligent torque vectoring. Power was supplied by a lithium-ion battery with a capacity of 9.1 kWh. The electric range was 50 kilometers (31.1 mi). The Audi e-tron Spyder consumed 2.2 liters of fuel per 100 kilometers (106.9 US mpg), corresponding to 59 grams CO2 per km (95.0 g/mi). The dynamic performance figures: from 0 to 100 km/h in 4.4 seconds. Top speed was capped at 250 km/h (155.3 mph).
2013: Audi nanuk quattro concept
Audi showed the Audi nanuk quattro concept technology study at the 2013 IAA in Frankfurt am Main. The two-door coupe crossover concept combined the dynamics of a high-performance sports car with Audi's quattro expertise – on the road, on the race track and off-road.
It was powered by a V10 TDI mounted longitudinally in front of the rear axle. The powerful 5.0-liter diesel produced more than 400 kW (544 hp) and developed 1,000 Nm (737.6 lb-ft) of torque starting at 1,500 rpm. It used a twin-turbo register charging unit and the Audi valvelift system (AVS) – technologies which have since undergone intensive further development by Audi. Its common rail system developed up to 2,500 bar of pressure. The Audi nanuk quattro concept sprinted from zero to 100 km/h in 3.8 seconds and reached a top speed of 305 km/h (189.5 mph). It consumed on average just 7.8 liters of fuel per 100 kilometers (30.2 US mpg).
2005 to 2009: Additional show cars with TDI engines
Audi presented additional studies with TDI engines to the public besides the show cars described above. The Audi allroad quattro concept at the 2005 Detroit Auto Show presented the at that time new V8 diesel, which entered production shortly thereafter. In 2008, Audi showed the Cross Coupé quattro in Shanghai and the Cross Cabriolet quattro in Los Angeles. The closed two-door used the 2.0 TDI; the Cabriolet the three-liter diesel. The Sportback concept was on the Audi stand in Detroit in early 2009. The precursor of the Audi A7 Sportback had the 3.0 TDI clean diesel with SCR (selective catalytic reduction) catalytic converter under the hood.
The equipment and data specified in this document refer to the model range offered in Germany. Subject to change without notice; errors and omissions excepted.