2007 Audi Q7 Review

Specifications

If there’s one thing that Audi is best known for, it’s got to be
quattro allwheel drive. It started with a single car, the Coupe Quattro, which launched an entire generation of future products by proving on the road and rally circuits that all wheel drive wasn’t just for pickups and tractors. There is a prevalent driving force behind today’s Audi. Emphasis is still put on quattro, but much of the firms’ effort is put into developing power plants, and there’s no stronger sign than the Q7 V12 TDI Concept that debuted at this year’s NAIAS. Audi already committed to producing this vehicle back at Paris, so the version you see here is for show purposes only. It’s sort of a teaser to goad Americans into believing that diesel technology is the way of the future.

Up until now, the king of diesel engines in passenger cars hasto have been VW’s 5.0-liter V10 TDI that served duty in Volkswagen’s Touareg around the world and the Phaeton in Europe, but it’s ceding its reign over to Audi. The engine in the Q7 not only incorporates an extra two cylinders, but gains an entire liter in displacement; it’s a V12 and has a volume of 6.0 liters. Compared to Audi’s racing engine, it’s a half liter larger, but the motor in the R10 TDI makes over 650 horsepower, whereas the Q7 puts out 500 horsepower and 737 lb-ft of torque. That’s about 100 horsepower off the mark of Mercedes’ twin-turbocharged V12 in the “600″ series luxury cars and trails by a mere 1 lb-ft. Remember, this is a diesel, not a gasoline engine!

Though the Q7 shares the same number of cylinders as Audi’sracer, it’s not a direct development from the engine in that car. It has the same bore and stroke as the smaller 3.0-liter TDI engine, but overall it measures in at just 664 mm (26.1 inches) in length - a particularly compact size for a V12 engine. Audi needed to keep it small in order to fit it in the tightly packed Q7 engine bay. The link to the racing R10 is stronger in other ways, namely the technology that Audi learned in developing better materials, better fuel delivery, and better forced aspiration techniques. The crankcase for the V12 engine is made out of GJV-450, which, despite its name, isn’t some sort of rare earth element, but rather a special material that’s made partially from cast iron and vermicular graphite. This material is 40-percent stronger than pure cast iron, and twice as durable, allowing Audi to trim down the thickness of the cylinder walls without worry. Strength is important in diesel engines which run at super-high compression ratios, therefore other areas of the V12’s engine such as the twin cylinder heads and crankshaft are made of equally exotic materials.

What makes the Q7’s diesel such a mighty force to be reckonedwith can be traced down to its fuel injection system and its big, high-pressure turbochargers. Through the use of piezoelectric fuel injectors, the system is capable of delivering extremely precise amounts of fuel multiple times in the combustion cycle. Pilot injections (those before the main injection) and post combustion (after main injection) are made which not only burns fuel more cleanly, but it also helps smooth out the generally rough nature of diesel engines. And then there are the turbos. Two of them are used here, one for each bank of cylinders, and each has variable geometry vanes. The turbochargers give a total of 2.6 bar of boost, which, quite frankly, is incredible. But even more impressive is the fact that the peak torque of 737 lb-ft is available between 1,750 to 3,000 rpm.

Concerning emissions, Audi is confident that the Q7 V12 TDI would be able to pass stringent North American emissions regulations thanks to the use of Bluetec. Since the announced collaboration with DaimlerChrysler, doors have opened up for Audi and Volkswagen concerning diesel in North America. However good the now familiar urea-based Bluetec system is at reducing emissions, not all credit can go to DCX, as Audi’s engineers did plenty of work themselves to ensure the engine be as clean as possible. The V12 is capable of recirculating 50-percent of its exhaust gasses at partial throttle; exhaust gasses are inert and would therefore not cause further pollution. Meanwhile, dual intercoolers help to keep the fresh air coming into the combustion chamber as cool and as dense as possible improving combustion.

Audi didn’t do much to change the looks of the Q7 for its big unveiling, which to somewas a bit disappointing. The large three-row SUV did sport some changes to differentiate itself from the standard Q7, however, as did the V12 TDI model that was previously shown in Paris. It comes down to accessories, and most easily noticeable is the grille that has an egg crate pattern yet lacks the standard cross bar. The headlamps feature a ring of LED lights that form a halo around the main beam; likewise, the LED tail lamps have a different pattern, and the low-mounted brake lights are also different. A new set of bumpers includes deeper valances as well as flush-mounted tail pipes for a sportier look. They’ve finished it off with a large roof-mounted spoiler, massive chrome plated S6-style alloy wheels and a white paint job that glimmers and sparkles like fresh snow in the sun. Think of it as a showy, custom-made version for a well-known celebrity. Perhaps it’s for Seal, who performed at the concept’s unveiling. He currently drives a Q7 and was openly enthusiastic about getting his hands on the new V12 TDI - who wouldn’t be?

Like the exterior, the interior of the Q7 Concept looks more like a customized car than one of Audi’s usual concepts. Practically all surfaces, including the buttons and dash trim are trimmed in an off-white/cream leather or white-dyed plastic. Even the carbon fiber has a white-colored weave! In fact, the only things that aren’t white are the aluminum pedals, accent pieces, the piping on the carpets, the MMI display screen, the gauges, the anthracite headliner and the little LCD displays for the climate control. The all-white scheme looks cool and is certain to keep cool when baking under thousand-watt showlights, but in the real world it’d keep its luster for all of five seconds before going dingy and dark. Other notable changes include the addition of heavily-bolstered Audi S6 seats, and a new instrument cluster that features a revised information center that displays a G-force meter in addition to the usual trip computer functions. Anyone who drives this should use the built-in speed warning device, given the masses of power and the 220 mph speedometer.

The Q7 V12 TDI Concept is a technological showcase designed to generate hype, and even though it’ll be on the road in Europe by the end of this year it has little by the way of relevance for North America. If it’s any consolation, Audi has already committed to putting a diesel Q7 into production by 2008. It won’t be the V12 TDI, but rather a 3.0-liter V6 TDI engine that makes a more realistic 233 hp (no torque figures yet, but estimated in the high 300s) and will feature Bluetec technology enabling it to be sold in all 50 U.S. States. It will offer an estimated 20 to 25 percent fuel economy improvement over the standard gasoline engine, although Audi didn’t specify if that was the 280-hp 3.6-liter FSI-V6 or the bigger 350-hp 4.2-liter FSI-V8. Either way, it’ll be a solid improvement in fuel economy and environmental friendliness over the gasoline engine, which should make it popular in today’s eco-centric market.