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Home | Green Cars News | Clean Diesel | 2011 Audi Q7 Gets New V6 Engines and Eight-Speed Transmission

2011 Audi Q7 Gets New V6 Engines and Eight-Speed Transmission

08 April, 2010 12:18:00

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Audi has made the 2011 Q7 SUV more powerful and efficient, with a choice of two new two gasoline V6 engines, one new V6 TDI and an eight-speed automatic transmission.

All the engines for the 2011 Audi Q7 combine two technologies: forced induction and direct fuel injection. A high-performance recuperation system that recovers energy during braking is also a standard item with all six- and eight-cylinder engines.

The second-generation 3.0 TDI, a new development, has effectively nothing in common with its predecessor – apart from plenty of power! It has a rated output of 176 kW (240 hp) and a constant 550 Nm (405.66 lb-ft) of torque all the way from 1,750 to 2,500 rpm. This V6 diesel accelerates the 2011 Audi Q7 from a standstill to a typical main-road speed of 100 km/h (62.1 mph) in 7.9 seconds and reaches its top speed at 215 km/h (133.59 mph) or, with adaptive air suspension, 218 km/h (135.46 mph). Its fuel consumption is impressively low, averaging 7.4 liters per 100 km (31.79 US mpg), which is equivalent to CO2 emissions of 195 grams per kilometer (313.82 g/mile). This is an improvement of 1.7 l/100 km or 19 percent.

The latest 3.0 TDI engine weighs much less than before: 198 kilograms (436.52 lb), a reduction of 20 kg (44.09 lb). A new chain-driven timing gear and a complex cylinder wall machining process have reduced internal friction. The new turbocharger is exceptionally responsive, making itself felt as rapid torque buildup. The common rail injection system has also undergone further development: it has a maximum operating pressure of 2,000 bar and can therefore inject fuel in an extremely precise spray pattern.

The crankcase and cylinder heads of the new 3.0 TDI have separate cooling water circuits connected together by valves. During the warm-up phase and when loads are not high, the coolant is not circulated in the engine block. This saves energy and raises the oil more quickly to its regular operating temperature. The new start-stop system switches off the engine when the 2011 Audi Q7 comes to a standstill.

Audi also offers its customers a second version of the V6 TDI: the 3.0 TDI clean diesel. It already meets the exhaust emission limits laid down in the Euro 6 standard, which does not come into force until 2014, and the tough US regulations as well. Sensors in the combustion chambers, a common-rail fuel injection system with a delivery pressure of up to 2,000 bar and a high-performance exhaust gas recirculation system keep untreated exhaust emissions to a minimum. A DeNox catalytic converter in the exhaust system reduces the remaining oxides of nitrogen by means of an additive. The 3.0 TDI clean diesel also develops 176 kW (240 hp) and has an impressive 550 Nm (405.66 lb-ft) of torque between 2,000 and 2,250 rpm. It takes the Q7 from a standstill up to 100 km/h (62.14 mph) in 8.1 seconds and gives it a top speed of 215 km/h (133.59 mph), or 218 km/h (135.46 mph) with adaptive air suspension. Its average fuel consumption is 8.4 liters per 100 km (28.00 US mpg).

The 2011 Audi Q7 4.2 TDI has also had its fuel consumption drastically reduced – from 9.9 (23.76 US mpg) to 9.2 liters per 100 km (25.57 US mpg) – by installing a 2,000-bar fuel injection system and minimizing internal friction. Yet at the same time the V8 diesel, with its unchanged power output of 250 kW (340 hp), delivers more torque than before. It now supplies a vigorous 800 Nm (590.05 lb-ft) between engine speeds of 1,750 and 2,750 rpm. The big TDI engine gives the Q7 performance figures worthy of a sports car. It accelerates from 0 to 100 km/h (62.14 mph) in 6.4 seconds and has a top speed of 242 km/h (150.37 mph).

New 3.0 TFSI
The new 3.0 TFSI gasoline engine embodies Audi’s downsizing strategy: replacing engine displacement with supercharging. Within the 90-degree angle formed by its cylinder blocks there is an engine-driven supercharger that compresses the intake air. Two charge-air intercoolers prevent the air temperature from rising, so that the engine draws in more oxygen for the combustion process. Vigorous thrust and spontaneous throttle response make the 3.0 TFSI engine, with its sonorous note, an ideal source of power for the large high-performance SUV from Audi.

Two versions of the supercharged V6 are available. The basic version develops 200 kW (272 hp) and has a maximum torque of 400 Nm (295.02 lb-ft) over a broad engine-speed range from 2,250 to 4,750 rpm. It accelerates the 2011 Q7 in 7.9 seconds from a standing start to 100 km/h (62.14 mph) and gives it a top speed of 222 km/h (137.94 mph), or 225 km/h (139.81 mph) with adaptive air suspension.

The more powerful version of the 3.0 TFSI delivers 245 kW (333 hp) and a torque of 440 Nm (324.53 lb-ft) between 2,900 and 5,300 rpm. 100 km/h (62.14 mph) are reached in 6.9 seconds, with powerful forward progress continuing until 243 km/h (150.99 mph) are reached; with adaptive air suspension the top speed is 245 km/h (152.24 mph). Both versions of the 3.0 TFSI are impressively efficient: in the EU fuel consumption test cycle they are content with 10.7 liters per 100 kilometers (21.98 US mpg). Compared with the previous engines, the 3.6 FSI and the 4.2 FSI, fuel consumption has been reduced by 1.4 and 2.0 l/100 km – 12 and 16 percent respectively.

Power transmission: eight speeds are standard
Audi has given all six- and eight-cylinder Q7 versions a new automatic transmission. The eight-speed tiptronic lowers fuel consumption by about 5%. It is based on the six-speed unit, but with another friction-clutch shift element added. Being able to shift between eight ratios keeps the jumps in engine speed low: the engine always runs close to its ideal operating point. All gear shifts are fast, flexible and take place extremely smoothly without delay.

At 7.25 to 1, the overall spread of ratios in the eight-speed tiptronic is unusually wide. In the lower ratios the Q7 accelerates powerfully; in the higher ratios it rolls along efficiently at low engine speeds.

To cut fuel consumption still further, the torque converter lockup clutch eliminates slip even at low engine speeds. Any engine vibration that could occur as a result is suppressed by the new damper in the torque converter until scarcely any trace can be detected.

Drivers can choose between the D and S programs – or make their own gear shifts at the transmission selector lever or the optional steering-wheel paddles. In combination with the 3.0 TDI the new eight-speed tiptronic achieves an exceptionally high level of efficiency. Its oil cooler is heated after a cold start by hot coolant from the engine’s cooling system. An electric oil pump makes operation of the Q7’s start-stop system possible: it maintains oil pressure in the hydraulic circuit when the engine stops, and closes the clutch for restarting.

The eight-speed tiptronic transmission transfers engine power to the quattro permanent all-wheel drive train. This splits the power in a sporty manner, with 40% going to the front and 60% to the rear wheels, but in certain on- or off-road situations, the mechanical-action center differential can direct up to 65% of the power to the front or up to 85% to the rear.

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