Maximum power of 380 bhp, consumption of just 8.2 L/100km
Singapore, 19 May 2011 – The new Volkswagen Touareg has been an outstanding success since its launch last year, and its appeal has now been enhanced with the introduction of the new Hybrid model.
When the Touareg Hybrid’s V6 TSI engine and E-motor work simultaneously (boosting), a total power of up to 380 bhp is generated with a maximum torque of 580 Newton-metres.
Yet, the vehicle sets standards among fully off-road capable SUVs with petrol engines with a fuel consumption value of just 8.2 litres per 100 kilometres. CO2 emissions are equally low: 193 g/km. The Touareg Hybrid can also be driven up to 50 km/h in purely electric mode − emissions-free.
The Hybrid drive combines the power of a classic eight-cylinder engine with the fuel economy of a six or four-cylinder engine. Performance is extremely strong: The Touareg Hybrid reaches a top speed of 240 km/h and accelerates to 100 km/h in just 6.5 seconds.
The drive unit of the Touareg Hybrid primarily consists of a supercharged V6 TSI (direct-injection petrol engine with 333 bhp), an 8-speed automatic transmission customised for hybrid, towing vehicle and off-road use, including torque converter, final drive units and centre differential, as well as the Hybrid Module integrated between the internal combustion engine and automatic transmission.
This module – the ‘heart of the hybrid’ – contains an E-motor (34.3 kW /46bhp) and a disengagement clutch. The Hybrid Module has a diameter of400 millimetres, is only 145 millimetres long and weighs just 55 kilograms.
The drive energy for the E-motor is stored in a Nickel Metal-Hydride (Ni-MH) battery at the rear of the Touareg in the spare wheel recess. With its nominal voltage of 288 V, the battery has an energy capacity of 1.7 kilowatt-hours (kWh) and a peak output power of 38 kW. The energy stored in the battery is sufficient to drive the Touareg over a distance of about two kilometres and up to a speed of 50 km/h in pure electric mode.
Parallel hybrid ideal for SUV use
Volkswagen deliberately chose a parallel hybrid drive configuration for the Touareg. In contrast to other possible hybrid systems, it assures excellent off-road performance and unlimited continuous climbing ability. Moreover, the parallel hybrid is more efficient than alternative hybrid concepts on long-distance and motorway journeys.
Compared to a conventional SUV of the same size and power, the hybrid concept delivers fuel savings of up to 25 percent in city driving. In combined mode driving – a mix of city, highway and motorway drives –development engineers calculate an average saving of 17 percent. Essentially, four parameters were exploited to achieve this fuel efficiency on the Touareg Hybrid:
Electric driving: Emission-free driving (as described, up to 50 km/h) by pure electric power reduces petrol consumption. In this case, the V6 TSI is not only shut off, but is also disengaged from the 8-speed automatic by a disengagement clutch to avoid drag torque losses.
Coasting: As soon as the driver releases the accelerator pedal, the V6TSI is disengaged from the transmission. This is even possible at higherspeeds (up to 160 km/h), i.e. on the highway as well. The Touareg ‘rolls’significantly longer, since drag torque losses are eliminated. When driversadopt an anticipatory style of driving, this has a direct positive impact onfuel economy.
Regenerative braking: During braking, the E-Motor − now operating as a generator – recovers kinetic energy, which is then stored in the high voltage battery.
Stop-Start system: The Stop-Start system integrated in the powertrain improves fuel economy, especially in urban areas and stop-and-go traffic.
The V6 TSI in detail
The Touareg’s remarkably rpm-friendly and responsive V6 TSI develops its 333 bhp of power between 5,500 and 6,500 rpm. At a low 3,000 rpm it generates a maximum torque of 440 Newton-metres from the 2,995 cc displacement of its six-cylinder with intercooler.
This maximum torque is maintained at a constant level over a very extended range of engine speed. And indeed up to 5,250 rpm. So it can be said that the V6 TSI offers the power and torque of an eight cylinder, but is significantly more fuel efficient.
The already very dynamic torque characteristic enabled by the supercharger becomes even more fascinating when the E-motor is used at low speeds. That is because the torque with boosting essentially jumps to 580 Newton-metres from a standstill – a dynamic side effect of the system designed for efficiency.
The high-voltage battery in detail
The Nickel Metal-Hydride (Ni-MH) battery used in the Touareg Hybrid reflects today’s best available energy storage technology in automobiles that offers unproblematic operation. Supporting the use of the high performance Ni-MH battery are its functional safety and ruggedness –studied and proven for years now – and its significant cost advantages.
The high-voltage battery is housed in a space-saving manner in the area of the original spare wheel recess. It consists of a total of 240 individual cells, as already mentioned generates a voltage of 288 Volt and offers an energy density of 1.7 kWh.
The high-voltage battery is maintained within an optimal temperature range by an auxiliary duct integrated into the Touareg’s interior ventilation system and two separate fans. A Battery Manager continuously monitors the charge by comparing data with the Hybrid Manager.
Steering, air-conditioning, braking – how it works without the V6 TSI
Ensuring that the Touareg Hybrid can also satisfy all convenience and safety-related functions in pure E-mode too, various components had to be fully re-developed. There is electro-hydraulic power steering, for example, which does not rely on the servo pump driven by the internal combustion engine. Instead, in this case an electric servo pump supplies the necessary hydraulic pressure.
An auxiliary electric vacuum pump that is used during electric driving guarantees that the vacuum supply required by the brake booster is maintained. In addition, an electric high-voltage air conditioning compressor in the Touareg Hybrid assures pleasant interior temperatures even when the V6 engine is shut off.