New Audi A6 Cuts Fuel Consumption About 15% Across Whole Model Range

12 August 2008

The Audi A6.

Audi has upgraded its luxury class A6 model, adding more efficient engines—including the new 3.0L TFSI supercharged engine (earlier post)—and cutting fuel consumption by about 15% across the whole model range. An improved suspension and new high-tech assistance system give the driver even greater control over the car. The revamped A6 will be launched in the German market in late summer.

The A6 now offers a selection of six gasoline and four diesels with direct fuel injection and FSI, TFSI and TDI technologies in a choice of four, six or eight cylinders. At the lower end of the diesel program is the four-cylinder 2.0 TDI engine, which is available in two versions: the 125 kW (170 hp), expected in fall 2008, and the 100 kW (136 hp). The basic version is an efficient e-model—the 2.0 TDIe—which uses a six-speed manual shift or automatic multitronic transmission to deliver 320 Nm (236.02 lb-ft) of torque to the front wheels.

With multitronic transmission it accelerates from 0 to 100 kph (62.14 mph) in 9.9 seconds, and continues on to a top speed of 204 km/h (126.76 mph). Average fuel consumption with a manual shift gearbox is 5.3 L/100 km (44.38 US mpg), equivalent to CO₂ emissions of approximately 139 grams per kilometer (224 grams per mile).

The power steering pump operates on demand; the alternator regenerates electrical energy when coasting thereby reducing load off the engine. By lowering the ride height by 20 millimeters (0.79 in) and other aerodynamic fine-tuning, the drag coefficient has been reduced to cD = 0.28.

The two V6 TDI engines—2.7 TDI with 140 kW (190 hp) and 3.0 TDI with 176 kW (240 hp)—have peak torques of 380 Nm (280.27 lb-ft) and 450 Nm (331.90 lb-ft), respectively. A common rail fuel injection system with rapid-action piezo injectors supports an injection pressure of 1800 bar (26,106.79 psi).

The smallest gasoline engine is the 2.0 TFSI, a 125 kW (170 hp) turbocharged four-cylinder unit. On the other end of the spectrum is the 4.2 FSI, a 257 kW (350 hp) V8 engine. Audi V6 models can be equipped with one of its two new 2.8 liter FSI engines; the 140 kW (190 hp) or the 162 kW (220 hp). Both engines feature the Audi Valvelift System (AVS), which manages the inlet valve timing so that there is more torque and less fuel consumption. Regardless of which 2.8 FSI engine the A6 sedan is fitted, average fuel consumption is 8.2 liters per 100 kilometers (28.68 US mpg) for the 190 hp, 6-speed manual shift or 8.4 liters per 100 kilometers (28.00 US mpg) for the 220 hp multitronic CVT.

The new 3.0L supercharged TFSI delivers 213 kW (290 hp) power output with a broad and flat torque curve from 2500 rpm to 4850 rpm at 420 Nm (309.78 lb-ft). The A6 sedan with 3.0L TFSI accelerates from 0 to 100 km/h (62.14 mph) in 5.9 seconds and keeps on going as it presses to its electronically-regulated maximum speed of 250 km/h (155.34 mph). Fuel consumption is 9.5 L/100km (24.76 US mpg) on the EU cycle.

Any manual-shift A6 with Driver Information System, even the 2.0 TDIe, can opt to have the shift indicator displayed in the instrument panel. The icon lets the driver know which gear is most economical under actual circumstances. Audi quattro four-wheel drive is available on all engines with 140 kW (190 hp) or above and is standard equipment on high-end aggregates. This latest generation quattro features a newly emphasized rear-end design. Under normal conditions, the torque split is 40% to the front wheels and 60% to the rear. The mechanically-operated Torsen differential immediately diverts most of the power to the axle, providing better traction whenever the need arises—in extreme cases, up to 65% to the front or 85% to the rear.