The new Volkswagen Jetta Hybrid has made its world debut at the 2012 North American International Auto Show in Detroit, bringing electric drive to a new class of Volkswagen. Propulsion comes from a high-tech 1.4-litre TSI 150 PS petrol engine and a 20 kW zero-emissions electric motor. Together, these provide not merely fuel consumption that is around 20 per cent better overall than an equivalent petrol-powered vehicle (at 45 mpg US - around 54 mpg Imperial), but also sporty performance, with the benchmark 0 to 60 mph sprint taking less than nine seconds.
Like the Touareg Hybrid, the Jetta is a parallel hybrid, using a decoupling clutch that can disengage the petrol motor for pure electric drive (or when coasting or braking), disengage the electric motor (for higher speeds or when the battery charge is low), or combine the two units for maximum power. Using electric power alone, the Volkswagen Jetta Hybrid can be driven at speeds of up to 70 kmh (44 mph) and over a distance of two kilometres (1.3 miles), depending on conditions. For maximum performance, both the TSI engine and the electric motor combine, giving peak power of 170 PS. This is the first use of the 1.4-litre turbocharged engine in America, and it offers the same power and more torque (250 Nm, 184 lbs ft) than the normally aspirated 2.5-litre engine that is commonly used in the Jetta there.
A lithium-ion battery supplies the energy for the electric motor. It is located behind the rear seat bench, making no compromises on interior space. The battery is made up of 60 individual cells, each with an energy capacity of five Ah. Together they produce a nominal voltage of 220 Volts and an energy capacity of 1.1 kWh and weigh 38.5 kg. Cooling is provided by an integrated fan, operated by the battery's own management system that performs diagnostic, monitoring and safety functions, including disconnecting the battery in the event of an accident.
Power is directed to the front wheels via a seven-speed dual clutch DSG gearbox, which is efficient and lightweight, at 74 kg. Despite the extra weight of the battery, electric motor and extra safety modifications to the vehicle's structure, the Volkswagen Jetta Hybrid weighs only 100 kg more than the non-hybrid Jetta at less than 1,500 kg in total.
Provided the battery contains sufficient charge, the Volkswagen Jetta Hybrid is switched to electric drive mode either automatically (at speeds of up to 60 kmh or 37 mph) or at the press of a button next to the gear lever (up to 70 kmh or 44 mph).
When the driver releases the accelerator pedal at higher speeds (up to 135 kmh or 84 mph) the TSI engine is decoupled, reducing drag torque losses, and maximising fuel efficiency. Under braking, the Volkswagen Jetta Hybrid switches to a battery regeneration mode, which decouples the TSI engine and uses the electric motor as a generator. The generating power of the motor rises with increased brake pedal travel. At higher speeds, or when the battery charge is depleted, the TSI motor provides extra power to recharge the battery, however even in these situations the charging is interspersed with electric driving phases to maximise fuel efficiency.
Externally, the Volkswagen Jetta Hybrid can be identified by aerodynamic modifications including a new front spoiler, a rear diffuser and a rear spoiler that help to improve the car's Cd value by 10 per cent. There are also new headlights with LED running lights, LED rear lights and unique 15-inch alloy wheels with low rolling resistance tyres. 'Hybrid' badges adorn the front wings, bootlid and modified front grille, where the Volkswagen logo is presented on a blue background for the first time.
The interior of the Hybrid is very much like that of any other Jetta, although the electric drive, along with a newly designed exhaust system, an acoustic windscreen and thicker front side windows help to make this the quietest vehicle Volkswagen has ever offered in this class.
One key interior difference is in the instruments. If the driver selects the 'Hybrid' menu in the multifunction display, the current drive mode is shown, while a meter indicates energy flow via arrows. The same screen also shows the battery charge state. Beneath the energy flow diagram is what is known as the ePower meter, which indicates the power provided by the electric motor.
The tachometer is replaced by the Power meter, a multifunction display on the left of the instrument cluster. This informs the driver of the operation of the hybrid system: 'Ready', 'Charge', 'Eco', 'Boost' or 'TSI'. The audio system, meanwhile, has a 'zero emissions' menu. This offers a graphical display of the past 30 minutes of driving time, with a bar showing emissions each minute: a full, 100 per cent bar represents no emissions at all.
Standard equipment on the US-spec SE model includes a 2Zone climate control system that works without the TSI engine running, a 'Premium 8' sound system, Bluetooth phone integration, MDI interface for iPod connectivity and a leather-wrapped multifunction steering wheel. Moving up to SEL1 specification adds 16-inch alloy wheels, a glass sunroof, RNS 315 satellite navigation, electric driver's seat adjustment, heated front seats and keyless entry. The top SEL2 specification adds to this further, with 17-inch wheels, fog lights, bi-xenon headlights with cornering function, a reversing camera and a 400-Watt Fender sound system.
The Volkswagen Jetta Hybrid launches in North America in November 2012; there are no current plans to sell this model in the UK.