Completely new electronic systems also simplify off-road driving in the Tiguan. The particularly agile and dynamic SUV uses an innovative network of assistance systems with the name of “Offroad Mode”. Just one touch of a switch activates a whole armada of safety features, supporting the driver in a multitude of situations.

THE TIGUAN VERSIONS

Innovation: All engines of the Tiguan are 'charged'.
18 and 28 degrees: Two front ends with different entry angles.

Five motors. All the engine and body versions of the Tiguan have to “bite” the dust of Namibia in this final test. Volkswagen will be offering the SUV – and this is unique so far – exclusively with 'charged' engines. The TSIs (petrol) output 110 kW, 125 kW and 147 kW; and the TDIs (diesel) develop 103 kW and 125 kW.

Two front ends. The two body variants of the Tiguan differ primarily in their front ends. The “Trend & Fun” and “Sport & Style” versions are designed for a maximum entry angle of 18 degrees in front. The “Track & Field” Tiguan that is tuned even more for off-road duty can assume entry angles of up to 28 degrees with its front end.

During the testing programme in Africa, however, the emphasis is less on engines and entry angles than  on final checking of the electronics and chassis.

THE TIGUAN CHASSIS

Front axle: McPherson system with aluminium support frame.
Rear axle: Innovative four-link rear axle is ideally matched to the four-wheel drive system 4MOTION.

Long before the first prototype was built, it had been decided that the new Tiguan should be an extremely active driving experience and a safe SUV. The development team pulled out all the stops to achieve this goal. The Tiguan now has to demonstrate in Africa that it achieves neutral to lightly understeering handling and an unusually low roll angle. Furthermore, the road holes along the edge of the Namib Desert should once more test how well the highly dynamic driving characteristics and excellent ride comfort interact under the hardest conditions. Because the demands on the car were clearly stated in the specification: to set benchmarks in dynamics, comfort and active safety. These goals were foremost in chassis development:

• Agile driving behaviour
• Very good vibration behaviour and ride comfort
• Low roll angle with harmonic roll dynamics
• High driving dynamic stability
• Good Off-road handling

Front axle. The demands are achieved with a chassis layout that sets standards in this class: at the front end, the Tiguan has a McPherson axle specially optimised for the SUV with lower A-arm steering linkage and the wheels hung from damper struts. The axle is located with a one-piece aluminium sub frame.

Rear axle. The four-link rear axle has also been adapted to best suit the permanent four-wheel drive system 4MOTION. The four-link rear axle of the Tiguan is specially intended for this combination. The extremely robust, but at the same time dynamically laid out axle geometry has already proved itself in the Passat 4MOTION. However, to cope with the stresses of off-road driving, the Tiguan has an entirely newly developed and weight-optimised high-strength steel sub frame instead of the equivalent aluminum component.

The rear axle of the front-wheel drive Tiguan has been modified correspondingly. Items no longer found on-board include: Cardan shaft, rear final drive and drive shafts. But the sub-frame is utilised in both drive variants. The innovative modular system of this rear axle has a decidedly positive effect on costs.

For the rear axle, newly developed shock absorbers were developed with increased oil volume; a favourable temperature level makes the absorbers well equipped for even the toughest off-road use. Like the front damper struts, also newly developed, both components provide for exceptionally good ride comfort properties.

A new generation of steering. A technological highlight in the indirect chassis area is the completely new generation of electromechanical power steering. A decisive advantage of the system: Despite the very precise steering feeling, even in off-road operation no jolts whatsoever are transmitted to the steering wheel. Primarily responsible for this is a newly constructed steering gear.

Wheels and tyres. Providing contact to the road or trail on the base versions of the Tiguan are 16-inch wheels with 215/65 R16 tyres. The “Sport & Style” Tiguan has, as standard, 17-inch alloy wheels and 235/55 R17 tyres. Optionally available, will be 18-inch wheels with tyres in 235/50 R18 format.

TIGUAN ELECTRONICS

Innovation: First Volkswagen with a new generation radio and navigation system.
Safety at the press of a button: off-road switch activates network of assistance systems.

Also in the area of electronics, the Tiguan was designed to set new standards in the compact SUV class. Typical of Volkswagen is the high standard it sets for making the interface to the driver as comfortable as possible. An example of this on the Tiguan is a newly designed radio and navigation system generation. The software and hardware of this new system fulfill the highest demands for operation, sound and the multitude of functions offered.

The RNS 510. A glance at the top device – a radio navigation system with the designation RNS 510, emphasises this impressively. The RNS 510 is controlled using fixed menu buttons, two knobs and a touch screen for the numerous information, entertainment and system functions. In this case a rear-view camera eases the view behind, a standard fitting.

The hardware of the RNS 510 includes a 6.5” wide VGA colour display with 800 X 480 pixels and outstanding brilliance. A PC processor with 400 MHz and its own graphic processor enable fast computing. The navigation and entertainment data are saved on a 30 GB hard disc. It is also possible to incorporate accessories into the RNS 510 like the telephone control, an iPod and other MP3 players. Combination with a Dynaudio sound system is also possible.

Off-road navigation. A further innovation of the RNS 510 is a specially developed off-road navigation system. This mode makes it possible to record up to 500 route points during a journey, even in non-digitised areas. This allows the driver to find his or her way back from off-road adventures into any desert or steppe. In edit mode, the driver can modify the route as desired. A glance at the map in the RNS 510 display offers the required orientation.

Park Assist. The further countless high-end technologies on-board the Tiguan include the world’s first park steering assistant to be installed in a SUV. This is called Park Assist and enables automatic steering into a parking space.

Off-road Mode. The core capability of a SUV – off-road function – will also be dealt with and perfected electronically in the new Tiguan. And this through just one switch, which activates the Off-road Mode. This will be offered exclusively on the Tiguan “Track & Field” and will improve off-road vehicle handling significantly. The initial idea behind the “Offroad Mode” was that all key off-road support functions should be activated by a central user control. Specifically, one switch activates the “hill descent assistant” (for optimal control on slopes), “adaptation of driver’s pedal characteristic” (for finer gradations of torque), “EDS adaptation” (electronic differential locks are activated at the slightest slip), “ABS adaptation” (improved braking action on loose road materials), “hill climb assist” (support when climbing and protection of the clutch) and – in conjunction with automatic transmission – “gear preselect” (including optimal engine braking action). These numerous functions involve up to five ECUs that manage the systems.

The pushbutton itself is connected to the engine controller. From there, the information “Offroad Mode active” is communicated to other ECUs via the vehicle’s CAN bus. For safety reasons, the function has to be reactivated after each ignition cycle.

Just how “intelligently” the electronics react is demonstrated by considering an off-road driving situation that is not all that uncommon: An engine stall can even happen to professional drivers off-road. This deactivates the Off-road Mode, and assistance systems are turned off. But the electronics of the Tiguan detects this as a “stall” and when the engine is restarted all off-road assistance systems are up and running again immediately.

The new Volkswagen Tiguan is due to be released in Europe in 2008, following its debut at this year's Frankfurt Motor Show. As usual for Volkswagen, it will be introduced worldwide, including Australia. The Next Car team expect to see the Tiguan available locally in late 2008.