In the compact class, Audi set another milestone in 2001: The A2 1.2 TDI achieved an average fuel consumption of 2.99 liters/100 km (78.67 US mpg). The compact A2 with its lightweight aluminum body featured a three-cylinder diesel engine with 1.2 liters displacement. A derivation from its big brother, the 1.4 TDI, it generated 45 kW (61 hp) and 140 Nm (103.26 lb-ft) of torque. The A2 3L TDI was the world’s first five-door car with fuel consumption of under three liters per 100 kilometers – and remains so to this day. In 2003, Audi also produced a more powerful cousin of its 1.9-liter TDI in the shape of the 2.0 TDI.
New generation: The 3.0 TDI
In large engines too, Audi vigorously advanced its technology. A 4.0-liter V8 with 202 kW (275 hp) was introduced in 2003 that anticipated some of the technical details of the new generation of V engines. The first full-fledged member of this family followed a year later in the shape of a new V6 TDI with 3.0 liters displacement. Its attributes – 90 degrees cylinder angle, 90 mm cylinder spacing, camshaft chain drive on the rear side – are standard features now in the new family of Audi V engines.
The three-liter engine with an output of 165 kW (224 hp) was equipped with common rail technology and innovative piezo injectors. These can inject very small doses of fuel, and by virtue of extremely fast opening and closing can deliver multiple separate pre-, main- and post-injections. When a voltage is applied to piezo crystals, they slightly expand in a fraction of a millisecond. In the injector, several hundred tiny piezo disks are stacked on top of each other, and the expansion of this stack is transferred directly to the injection needle.
Piezo injectors can thus produce precisely regulated increases in pressure and a uniform combustion process, which has brought engine acoustics into the region of gasoline engines. Another innovation was a particulate filter to clean the exhaust gas. In 2007/2008 the new four-cylinder 2.0 TDI too was equipped with a common rail system including piezo injectors. In 2009 this became the standard technology in all diesel engines.
Richard Bauder, who is in charge of diesel development at Audi, proudly takes stock of what has been achieved to date: “In 1989 we started out with 900 bar of injection pressure; today we’re at 2,000 bar. During this period, our TDI units have increased by more than 100 percent in power output and 70 percent in torque relative to a given displacement. At the same time, emissions have been reduced by 98 percent.” In the past 20 years, the TDI has experienced impressive growth: During this period, Audi has produced more than five million of these engines. Taking all makes into account, the TDI principle today powers every second passenger car built in Europe.
The TDI units marketed by Audi today are amazingly well-rounded performers – clean and efficient, dependable, refined, comfortable, and powerful. In motorsport, the world’s toughest test lab, they are proving how closely efficiency and dynamics are related at Audi.
The R10 TDI racing car, whose V12 diesel engine delivers more than 480 kW (650 hp), has won the Le Mans 24 Hours three times in a row starting in 2006. Its successor, the R15 TDI with a V10 diesel engine, has been earning top rankings right from its debut in 2009.
In production cars too, TDI engines from Audi excel with their muscular power. The top version of the Audi Q7 is equipped with the world’s strongest production diesel engine. The V12 TDI generates 368 kW (500 hp) and 1,000 Nm (737.56 lb-ft) of torque with its 6.0-liter displacement, endowing the big SUV with the performance of a sports car.
The 2.0 TDI with 125 kW (170 hp) and 350 Nm (258.15 lb-ft) of torque is another sporty engine. It delivers lively power and refinement, and thus lends brilliance to the dynamic TT and the TT Roadster. The lightweight, mainly aluminum bodies of this model series contribute to its superior driving performance: The TT Coupé, with quattro permanent all-wheel drive as standard equipment, accelerates in 7.5 seconds from zero to 100 km/h (62.14 mph) and attains a top speed of 226 km/h (140.43 mph). Yet on average it gets by on only 5.3 liters of diesel fuel per 100 km (44.38 US mpg).
New generation: The 3.0 TDI
In large engines too, Audi vigorously advanced its technology. A 4.0-liter V8 with 202 kW (275 hp) was introduced in 2003 that anticipated some of the technical details of the new generation of V engines. The first full-fledged member of this family followed a year later in the shape of a new V6 TDI with 3.0 liters displacement. Its attributes – 90 degrees cylinder angle, 90 mm cylinder spacing, camshaft chain drive on the rear side – are standard features now in the new family of Audi V engines.
The three-liter engine with an output of 165 kW (224 hp) was equipped with common rail technology and innovative piezo injectors. These can inject very small doses of fuel, and by virtue of extremely fast opening and closing can deliver multiple separate pre-, main- and post-injections. When a voltage is applied to piezo crystals, they slightly expand in a fraction of a millisecond. In the injector, several hundred tiny piezo disks are stacked on top of each other, and the expansion of this stack is transferred directly to the injection needle.
Piezo injectors can thus produce precisely regulated increases in pressure and a uniform combustion process, which has brought engine acoustics into the region of gasoline engines. Another innovation was a particulate filter to clean the exhaust gas. In 2007/2008 the new four-cylinder 2.0 TDI too was equipped with a common rail system including piezo injectors. In 2009 this became the standard technology in all diesel engines.
Richard Bauder, who is in charge of diesel development at Audi, proudly takes stock of what has been achieved to date: “In 1989 we started out with 900 bar of injection pressure; today we’re at 2,000 bar. During this period, our TDI units have increased by more than 100 percent in power output and 70 percent in torque relative to a given displacement. At the same time, emissions have been reduced by 98 percent.” In the past 20 years, the TDI has experienced impressive growth: During this period, Audi has produced more than five million of these engines. Taking all makes into account, the TDI principle today powers every second passenger car built in Europe.
The TDI units marketed by Audi today are amazingly well-rounded performers – clean and efficient, dependable, refined, comfortable, and powerful. In motorsport, the world’s toughest test lab, they are proving how closely efficiency and dynamics are related at Audi.
The R10 TDI racing car, whose V12 diesel engine delivers more than 480 kW (650 hp), has won the Le Mans 24 Hours three times in a row starting in 2006. Its successor, the R15 TDI with a V10 diesel engine, has been earning top rankings right from its debut in 2009.
In production cars too, TDI engines from Audi excel with their muscular power. The top version of the Audi Q7 is equipped with the world’s strongest production diesel engine. The V12 TDI generates 368 kW (500 hp) and 1,000 Nm (737.56 lb-ft) of torque with its 6.0-liter displacement, endowing the big SUV with the performance of a sports car.
The 2.0 TDI with 125 kW (170 hp) and 350 Nm (258.15 lb-ft) of torque is another sporty engine. It delivers lively power and refinement, and thus lends brilliance to the dynamic TT and the TT Roadster. The lightweight, mainly aluminum bodies of this model series contribute to its superior driving performance: The TT Coupé, with quattro permanent all-wheel drive as standard equipment, accelerates in 7.5 seconds from zero to 100 km/h (62.14 mph) and attains a top speed of 226 km/h (140.43 mph). Yet on average it gets by on only 5.3 liters of diesel fuel per 100 km (44.38 US mpg).