The new Volkswagen Jetta Hybrid , purely for the North American market, has made its world debut at the Detroit Motor Show.
Propulsion comes from a 1.4-litre TSI 150 PS petrol engine and a 20 kW zero-emissions electric motor. Together, these provide fuel consumption that is around 20 per cent better overall than an equivalent petrol-powered vehicle (around 54 mpg Imperial or 45 mpg US), and also sporty performance, with the 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 Jetta Hybrid can be driven at speeds of up to 44 mph and over a distance of 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 located behind the rear seat supplies the energy for the electric motor. 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 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 Jetta Hybrid is switched to electric drive mode either automatically (at speeds of up to 37 mph) or at the press of a button next to the gear lever (up to 44 mph).
When the driver releases the accelerator pedal at higher speeds (84 mph) the TSI engine is decoupled, reducing drag torque losses, and maximising fuel efficiency. Under braking, the 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 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.
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.
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 two zone 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 Jetta Hybrid launches in North America in November 2012; there are no current plans to sell this model in the UK.