Volkswagen of America is now launching at the Los Angeles Auto Show the hybrid version of its Jetta sedan.
The German hybrid sedan is powered by a high-tech 1.4-liter turbo petrol engine (TSI) and a zero-emissions electric motor (20 kw). Power transmission is managed by a 7-speed automatic DSG gearbox.
The Jetta’s hybrid drive allows for brisk accelerations (0-60 mph in less than 9 seconds per VW) and will return an estimated combined fuel economy rating of 45 mpg.
This means that the sporty saloon consumes about 20 percent less fuel than a comparably powered car with a conventional drive system.
Per Volkswagen, at the press of a button, the driver can also choose to drive the new Jetta Hybrid in pure electric mode at speeds of up to 44 mph and over a distance of 1.3 miles (depending on terrain and operating conditions).
The Jetta Hybrid is the second hybrid model from Volkswagen after the Touareg Hybrid.
All combined, the refined TSI engine, a newly designed exhaust system, use of an acoustic windshield, thicker side windows in front and various other measures have resulted in the quietest car Volkswagen has ever offered in this class.
The lithium-ion battery is constructed of 60 individual cells, each with an energy capacity of 5 Ah; altogether, they produce a nominal voltage of 220 volts and an energy capacity of 1.1 kwh. Weight for these batteries is 85.5 pounds (35.8 kg).
During braking, the Jetta Hybrid switches over to a battery regeneration mode, which ‘captures’ kinetic energy and feeds it into the battery as electrical energy.
The frequent alternation of discharging and charging cycles in hybrid operation requires high-performance battery cooling, which in this case is handled by a fan mounted directly on the energy storage device. The battery also has its own management system that performs safety, diagnostic and monitoring functions as well as temperature management.
Thanks to its lightweight drive components, the weight of the Jetta Hybrid was only increased by 100 kg despite the battery system. Together with additional safety modifications to the vehicle structure, the gross weight of the new Jetta Hybrid is still less than 3,307 pounds (1,500 kg).
The Volkswagen’s gasoline engine is shut off as soon as the car stops in city or stop-and-go traffic, provided that the driver presses the brake pedal and the battery is sufficiently charged. However, Volkswagen says the heating, air conditioning system and electric convenience systems such as the audio system continue to operate. Of special interest here is the fact that, unlike in conventional systems, not only is the Jetta’s engine stopped; the decoupling clutch also disengages the engine from the drivetrain to enable a pure electric driving mode when the car drives off again.
Volkswagen says a third of the fuel-saving potential in the Jetta Hybrid is realized by frequent deactivation of the TSI.
On the highway, as soon as the driver releases the accelerator pedal at higher vehicle speeds (up to 84 mph), the TSI is shut off and is also disengaged from the drivetrain via a decoupling clutch to eliminate drag torque losses in this driving situation. As a result, the Jetta Hybrid coasts further than is usual, without consuming any fuel.