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There are currently three main categories of off-road vehicles: conventional models with distinctly off-road equipment, lifestyle SUV’s with many street features, and those which want to master both types of terrain. Each category has its strengths, but they often involve compromises. Not so with the Touareg: Despite its authentic off-road capabilities, it offers the comfort of a luxury sedan along with the handling and drive features of a sports car for street driving.

Ideal starting conditions in a rapidly growing market

The Touareg is positioned as a high-end off-road vehicle - a strongly expanding segment. In 2000, approximately 700,000 vehicles of this category were sold world-wide, with a rising tendency. According to analyses, by 2004 annual sales of high-end SUV’s will reach 400,000 in North America alone. In Western Europe, forecasts predict 200,000 units by 2004.

The off-road vehicle market in Western Europe has also experienced constant growth. Across all SUV classes, annual sales rose from 362,000 vehicles in 1997 to 600,000 in 2001 - a growth rate of 13.6% per year. Volkswagen’s existing market presence ideally positions it to successfully establish the Touareg on the global market.

In addition, the new off-road vehicle meets the expectations of a clientele which does not want to make any compromises.

The Touareg meets these expectations in every way, setting standards in every performance category by offering superior street and off-road features as well as a broad selection of engines. This combination of state-of-the-art technology and luxury features is simply unique in this segment.

Four-Wheel Drive

The power of the Touareg engines is transmitted to the wheels via the continuous 4XMOTION four-wheel drive. This four-wheel drive guarantees not only outstanding off-road characteristics, but also a high degree of safety and dynamic potential on paved roads. Here, too, Volkswagen’s no-compromise SUV philosophy makes itself felt, supplementing authentic off-road features with the safety of a luxury sedan and dynamic of a sports car.

The 4XMOTION four-wheel drive in detail

The flow of power to the drive sprockets is handled by a transfer gearbox, which comes standard with off-road reduction, via a front-axle, rear-axle, and central differential. The rear-axle differential can be locked as an extra option; this feature comes standard with the central differential. The continuously adjustable multi-disc clutch of the central differential lock is automatically triggered by the running-gear electronic system. Depending on conditions, up to 100% of the drive force can be transmitted to one of the two axles. The driver has the option of completely activating the differential locks manually using a rotary switch in the cockpit, thus deactivating the lock’s automatic control. A standard four-wheel EDL supports the fine distribution of the drive force.

On-road: the benefits of the 4XMOTION four-wheel drive on paved roads

In normal situations - dry road, even grip, constant engine power - the 4XMOTION four-wheel drive is distinguished by a symmetrical, 50:50 distribution of power to the front and rear axles. But as soon as a wheel begins to slip, due to aquaplaning or a wet spot on one side of the lane, for example, the multi-disc lock of the central differential increases the flow of power to the axle in order to provide more grip. A four-wheel EDL (Electronic Differential Lock) also supports this adjusted power distribution.

The result is that the four-wheel drive equally enhances both the handling and the active safety. The Touareg thus handles like a luxury sedan; its driving behaviour is extremely safe and controllable; its curve stability is outstanding even under unfavourable road conditions.

The brake system is built to be absolutely stable. From a mechanical perspective, 16″ sliding caliper brakes and 17″ or 18″ fixed caliper brakes are used, depending on the engine version. Electronic features such as ABS, EBD (Electronic Brake-force Distribution), ESP, ASR and the braking assistant round out the system. On extreme slopes, a generously dimensioned foot-operated parking brake (duo-servo drum brake) holds the Touareg securely in place.

Off-road: the benefits of the 4XMOTION four-wheel drive off-road

On unpaved ground, the already described basic structure of the 4XMOTION four-wheel drive - front-axle and rear-axle differential - combine with the transfer gearbox, with central differential flanged onto the rear of the gearbox, to provide commanding propulsion. In addition, the Touareg also comes standard with a lock for the central differential as well as a reduction level. So equipped the Touareg can overcome even the steepest 100% (45º) slopes.

To activate the gearbox reduction level electrically, the driver simply sets the running-gear switch “Auto Diff” - located at the rear of the centre console - from fast mode “High” towards the right to “Low”. If there is a loss of traction at one axle, the central differential lock is automatically activated. The driver can also completely engage the lock using a rotary switch. The same principle applies to the optional electrically lockable rear-axle differential.

When starting up an incline, the brakes of the Touareg versions with manual gearbox act to support the motion. This hill-starting assistant then successively reduces the braking force while driving uphill, until the Touareg is moving securely in the desired direction. On steeply declining grades, the engine/braking-torque support in the ESP system prevents undesirable vehicle acceleration. The system thus insures regulated driving up and down slopes.

Up to 580 mm fordability and 45 longitudinal and 35º lateral inclination

The Touareg’s commanding climbing capability is not its only mark of off-road excellence. The possible lateral inclination is 70% / 35 (maximum static inclination 100% / 45). With a door-seal system designed to keep water out, waterproof headlights and connectors, a special guide for the intake air and engine ventilation, and sealed jointed shafts, the Touareg can ford depths up to 500 mm (580 mm with optional air suspension). The ramp angle for driving over a crest or other obstacle is 22 (air suspension: 27.2). Thanks to the short front and rear body overhangs, the angle of slope is 28 (air suspension: 33.2). And even the defining measurement of off-road performance, the ground clearance, promises commanding off-road handling at 237 mm (air suspension: up to 300 mm).

Running gear

The Touareg possesses a completely redeveloped high-performance running gear with single-wheel suspension. This intricately designed system forms the basis for the excellent street and off-road handling. The front boasts a dual-wishbone axle with upper aluminium links and lower steel links. The back of the Touareg also has a dual-wishbone axle, with forged aluminium links at the top and steel wishbones below.

While the Touareg V6 uses steel suspension, Volkswagen equips the standard Touareg V10 TDI with CDC (Continuous Damping Control) air suspension.

The CDC air suspension in detail

The air-suspension system, like the system used in the Phaeton, guarantees an extremely high degree of comfort and - with speed-dependent, automatic running gear lowering - the dynamic characteristics of a very sporty car when driving on paved roads. Thanks to the variable running gear height, it also improves the off-road handling while continuing to provide a high level of comfort.

The CDC air suspension always maintains the Touareg at a constant driving height. Four height sensors continuously measure the space between axle and body to keep the level between the front and rear axles even. As soon as the level deviates from the set position, the air volume of the suspension in the spring-absorber units is corrected by means of solenoid valves, a compressor and two accumulators. The Touareg’s four air-spring absorbers essentially consist of air-spring bellows, a roller piston and the regulated hydraulic absorber.

The electronic damping control (CDC) in detail

An extensive sensor system detects the body and wheel acceleration; the control system itself reacts to the slightest unevenness in the ground and compensates for it by adjusting the shock absorbers. The damping system adapts to the vehicle’s speed and current driving conditions, simultaneously minimising the tendency to roll or pitch. This positive effect also influences extreme acceleration or braking, for example, by reducing the body’s otherwise normal structural movements.

Running-gear switches grouped together in a control panel on the gearshift casing perform the basic adjustment of the air-spring and damping control. On the left is a rotary switch for the four-wheel drive, and on the right a similar switch for the air suspension. In between the two is a knob for adjusting the damping. Together these controls enable the manual adjustment of four different height levels and three different damping settings.

In “Auto Niveau” mode, which is primarily used on paved roads, the Touareg raises and lowers itself automatically based on vehicle speed. To optimise vehicle handling, the running gear sinks from 215 mm to 190 mm at 125 km/h. At 180 km/h, a height of 180 mm is automatically set. But the driver still has the option of setting other levels manually.

Engines

The Touareg’s introduction to the market is starting with a 3.2-litre V6 petrol engine and a 5-litre V10 TDI. The V6 engine achieves 162 kW / 220 hp and develops up to 305 Nm torque. Compared to the technically related 3.2-litre engine of the Phaeton and Golf R32, the Touareg’s six-cylinder was specially designed to be used in an off-road vehicle. Its adjustments include a modified oil pump with altered intake, an adapted sump for longitudinal and lateral inclinations, and a revised belt drive for improved fordability. The Touareg V6 reaches a top speed of 201 km/h (206 km/h with air suspension) and fulfils the EU 4 standard. In the U.S. it is classified Low Emission Vehicle (LEV).

One of the world’s most fascinating diesel engines is available with the completely new V10 TDI, which achieves 230 kW / 313 hp. Two additional engines will follow: a 2.5-litre, 5-cylinder TDI and a 4.2-litre V8 petrol engine.

All models come with a six-speed gearbox - manual or automatic depending on the engine - for transmitting power to the 4XMOTION four-wheel drive. With the automatic gearboxes, the driver can influence gear changes via DSP (Dynamic Shift Programme), the Tiptronic gearshift, or, depending on the model, the shift rocker buttons on the steering wheel.

V10 TDI - Five-litre displacement, biturbo charging, pump-jet injection

The completely new V10 TDI is one of the Touareg’s most noteworthy technical highlights. With its enormous generation of power - up to 750 Nm torque at just 2000 rpm - it can master even the most difficult off-road terrain. And the Volkswagen with this engine also offers sports-car handling and performance with comparatively low fuel consumption. The Touareg V10 TDI accelerates from 0 to 100 km/h in just 7.8 seconds, reaches a top speed of 225 km/h, but uses only an average of 12.2 litres of diesel for 100 kilometres.

In addition to the large displacement, the advanced pump-jet high-pressure direct injection (up to 2050 bar) and charging using a biturbo system with electrical charging-paddle adjustment play significant roles in this extraordinary power and performance development. Here is some information about the technological benchmark values for the V10 TDI, which is compressed in a 18.5:1 ratio: The cylinder spacing of the TDI is 88 mm, the bore 81.0 mm and the stroke 95.5 mm. The two five-cylinder banks are positioned at a 90º angle to each other, permitting a flat design. The length of 544 millimetres is just as compact.

An important requirement for the compact length of the engine is the control and auxiliary assemblies drive which, for the first time, has been constructed on one level in an aluminium wheel cassette which is acoustically decoupled from the crankcase.

In addition to the extraordinarily high torque and performance characteristics and the compact dimension, exemplary quiet running was one of the most important development goals. One of Volkswagen’s solutions for achieving it is to use a balancer shaft rotating counter to the crankshaft in the already low-vibration engine, depending on model. This balancer shaft eliminates the residual, free first-degree moments of inertia. Its effect is supported by six counterweights, manufactured from a tungsten alloy, which are fastened to the crankshaft. In terms of vibration, the V10 TDI thus runs at the level of a twelve-cylinder petrol engine.

In addition, the engine is characterised by a uniform ignition interval of 72º due to a split pin displacement of 18º on the crankshaft; this results in a favourable vibration behaviour, even under load.

The basic construction of the cylinder head is based on the pump-jet engines that Volkswagen has used in the past. However, for use in the Touareg’s V10 TDI, the already newly designed head was again redesigned as a crossflow model, enabling the inlet side within the V to be realised in between the two cylinder rows.

Direct injection itself takes on a key role: It optimises the mean pressures, the specific performance and the exhaust gas quality. The new pump jet used in the ten-cylinder engine is thus characterised by improved efficiency, a more compact solenoid valve and a significantly increased partial-load injection pressure. A completely redeveloped engine electronic system with two powerful control units enables precise modulation of the pump-jet injection elements, adapting the engine behaviour to the transmission of power. Advances that lead directly to an improvement in the handling and emission quality.

The innovative design of the exhaust-gas system, with its two chrome-plated tailpipes, is an essential element of the exhaust-gas cleaning system. The engine is also equipped with pneumatically controlled exhaust-recirculation valves for reducing emissions. Furthermore, oxidation catalytic converters close to the engine help optimise the raw emissions, which are already low in general. The Touareg V10 TDI fulfils the EU 3 exhaust gas standard.

Safety

With the new Touareg, Volkswagen is introducing an off-road vehicle which sets the highest standards for active and passive safety. From the perspective of active safety, the running gear - with single-wheel suspension, CDC air suspension, continuous four-wheel drive, commanding braking including ESP and braking assistant, and an optional tyre-pressure control system (TPC) - shows that even the safety reserves of a luxury sedan can be achieved with a luxury off-road vehicle. The same is true for active safety. Even its appearance, with a low centre of gravity, shows that compatibility with smaller vehicles and pedestrian protection were important design considerations. Volkswagen is not even offering a bull bar for the front end.

Development strictly in line with Euro-NCAP and US-NCAP

The crash requirements of Euro-NCAP and US-NCAP were taken into account during the Touareg’s development in order to protect both passengers and pedestrians. This is also true for the FMVSS 208 test, which is mandatory for all vehicles in the U.S. from 2003. In addition to all external standards, the Touareg also had to fulfil the extremely high crash requirements of Volkswagen.

The new off-road vehicle is thus characterised by very high energy absorption at the front and an extremely rigid passenger cell. Special protective measures for the interior include additionally closed bars in the still panels, extremely rigid A, B, C and D-pillars and pillar connections, and the use of highly sturdy steels and laser-welded seams. In addition, the door system was integrated into the Touareg’s crash structure. And the highly stable door construction provides maximum flank protection in the event of side impact.

Deformation characteristics for sharing the road with weaker users

Pedestrians and cyclists, the weakest users of the road, need to be protected as well as possible. The Touareg’s body design thus possesses a number of features which optimise pedestrian and cyclist protection. The bonnet, for example, consists of aluminium to provide optimum deformation characteristics. The mud wings are constructed of plastic and thus also absorb more impact energy. Defined deformation zones between the bonnet and motor covers selectively absorb energy in the event of impact. And the decision to forego both bull bars and an aggressive off-road design is proof of Volkswagen’s fundamental philosophy of providing the best possible crash compatibility between the weakest and strongest users of the road.

Touareg passengers are protected by a state-of-the-art electronic safety system, whose early-crash sensors control the two-level triggering intensity of the driver and front-passenger airbags based on the severity of the accident. Standard equipment includes, in addition to front and side airbags, curtain airbags which each cover the entire window surface between the A and C-pillars. The Touareg also boasts electrically triggered belt tighteners for window passengers (with force limiters for driver and front passenger), five three-point automatic belts, and belt height adjustment (B and C-pillars) for both front and rear passengers. A signal also notifies the driver if the belt is not fastened.

If small children are travelling in child-safety seats in the front-passenger seat, the front-passenger airbags can be deactivated via a switch. The Touareg’s rear seats offer Isofix fasteners for standard child-safety seats.

The protection system of the Touareg continues to work even following impact. As soon as a defined crash severity is exceeded or the airbags are triggered, all doors are automatically unlocked, the battery is isolated from the generator cable, the fuel supply and all high-power electrical units (such as the air conditioner) are shut down, and the hazard lights are switched on.

Related articles:

• Touareg - world premiere for Volkswagen’s top-class off-road vehicle at Paris Motor Show
• New Volkswagen Touareg breaks cover ahead of world debut at Paris Show
• New Volkswagen Touareg W12 Sport Edition
• Volkswagen Touareg gains power boost as new R50 model goes on sale
• The Touareg R50: World Premiere in Sydney

This entry was posted on Thursday, September 26th, 2002 at 09:52 and is filed under Volkswagen. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.