Lighter, more efficient and full of high-tech – The new Audi Q7

With its weight saving of 71 kilograms (156.5 lb), the body plays a crucial role in the lightweight construction of the new Audi Q7. The vehicle embodies the Audi Space Frame (ASF), construction method, with which the brand already has 20 years of experience. The multi-material ASF of the Q7 pursues a new approach that integrates large components from hot-formed steel and aluminum.

In steel hot-forming, the blanks are first heated in a furnace to roughly 900 degrees Celsius and fed into the press directly thereafter. In the water-cooled die, the sheet metal is quenched to about 200 degrees, creating a structure of extreme tensile strength for thinner walls and a correspondingly low weight. The hot-stamped components form the high-strength backbone of the Q7 passenger cell, reinforcing the transition from the front end to the interior, the side sills, the floor, the front section of the roof line and the B-pillars. Its share in the body cell is twelve percent.

41 percent share: The aluminum parts
The strut domes in the engine compartment that integrate the bearing support for the upper control arms, the neighboring hanger bracket, the connecting parts between sills and longitudinal members and the hinge reinforcements for the tailgate are all aluminum die-cast parts. Audi produces them itself. Aluminum sections allowing a very high absorption of energy in a collision are used for the front longitudinal members and other bearing parts in the front end, for the end sections of the rear longitudinal members and for two components in the rear.

Large areas of the occupant cell floor and luggage compartment, the rear wheel arches and the roof consist of aluminum sheet metal. The bottom line is that the lightweight material makes up 41 percent of the body structure. The doors, which are 24 kilograms (52.9 lb) lighter than the predecessor model’s, the front fenders, the hood and the tailgate are also aluminum sheet metal.

The production of the parts and their assembly involve different joining methods, including several newly developed ones. One of them is roller hemming of the side wall frame for manufacturing ultra-strong B-pillars. It allows slender flanges and correspondingly large, comfortable door cutouts.

In friction-element welding, another new method, a quickly rotating steel rivet passes through an aluminum sheet under high pressure and forms a firm connection with the steel panel lying underneath. Punch-riveting, clinching and self-tapping screws make up the so-called cold-joining techniques from the Audi repertoire.

Rigidity and acoustic comfort: The torsion rings
Three torsion rings – one horizontally and two vertically arranged – reinforce the front end, the areas around the C-pillars and the tailgate cutout of the new Audi Q7. They contribute significantly to the improved static and dynamic stiffness of the body that is retained even when the car is fitted with the optional panoramic glass sunroof. A solid cross member runs under the transmission tunnel at the level of the second row of seats.

The torsion rings form a substantial basis for precise driving and superior vibration comfort – the absence of disturbing vibrations and noises – in the interior. Another factor here is the elaborate decoupling of engines, transmissions and axles from the body.

Acoustic glazing in the front and side areas of the passenger cell and a comprehensive sealing concept for the doors and tailgate are standard features; at the windows, elegant trim strips cover the window slots. As an option, Audi offers insulating/acoustic glass, with tinted privacy windows being a further possibility. Details like outside mirrors placed on the top shoulders contribute to the best-in-class aeroacoustics.

The crash safety and occupant protection of the large SUV are also on the highest level. In the event of a collision with a pedestrian, pyrotechnic elements push the hood upwards in a flash, preventing the person’s head from striking against hard engine parts.

Slicing through the wind: The aerodynamics
Even with air resistance, the new Audi Q7 still moves to the head of its segment, with a best drag coefficient value of 0.31 with air suspension and lowering for highway driving. At the steeply sloping rear, the roof edge spoiler, the rails on the left and right of the rear window and small contours in the upper lights ameliorates the interruption of air flow.

The underbody also directs the air in a controlled way. A sturdy capsule that also serves as underbody protection fully seals the engine compartment from the road. The paneling underneath the passenger cell and the luggage compartment insulates against noise and protects the sheet metal against salt and stone chip damage, opening only at the exhaust system. Even the control arms of the rear axle are specially covered; mini-spoilers reduce lift here.

Loss of airflow through the engine compartment is also kept to a minimum
The Q7 3.0 TDI with 160 kW (218 hp), to follow a bit later, has a controllable cooling air inlet. A blind consisting of twelve slats, its housing is located between the Singleframe and the main water cooler. It is always closed when the need for a cooling airstream is low.