Toyota set a standard for hybrid drivetrains of hitching a low-displacement engine using Atkinson cycle valve timing to an electric drive motor through a virtual continuously variable transmission. Ford's hybrids use similar technology. However, for its first hybrid sedan, Volkswagen threw that formula out the window.
The 2013 Jetta Hybrid goes with Volkswagen's strengths, relying on direct injection, a turbocharger, and a dual-clutch gearbox for the internal combustion part of its hybrid drivetrain. With only 1.4 liters of displacement for its four-cylinder engine, this drivetrain looks like a miniature version of those found in Volkswagen's performance vehicles.
On the electric side, Volkswagen adds in a 20-kilowatt electric motor and 1.1 kilowatt-hour lithium ion battery pack, capable of driving the car under electric power. With regenerative braking and idle-stop, the Jetta Hybrid rates at 42 mpg city and 48 mpg highway, or a combined 45 mpg, according to EPA testing.
By itself, the engine's 150 horsepower and 184 pound-feet of torque should drive the compact Jetta adequately. But the electric drive system helps considerably with fuel economy, especially in city driving conditions. The combined system output rates at 170 horsepower.
Only minor cues distinguish the Jetta Hybrid from its internal combustion-only counterparts. A blue-tinted badge sits on the hood, while hybrid logos adorn the fenders. An aerodynamic treatment modifies the front intake, wheel skirts, and rear spoiler to take the coefficient of drag from 0.3 to 0.28.
The cabin also mirrors that of other Jettas in most respects, such as the heated leather seats, Fender audio system, and basic navigation of CNET's top-trim SEL Premium model. However, Volkswagen trades in the tachometer for a power gauge and adds a button labeled "E-mode." The trunk loses some space to the battery pack, which rides over the rear axle.
With the battery reasonably charged, the Jetta Hybrid started quietly, lighting up its gauges and center LCD while leaving the engine alone. The shifter for the seven-speed dual-clutch transmission includes, along with Drive, sport and manual shift positions, neither of which were really much use.
Rolling out, the Jetta Hybrid responded readily to its accelerator, and the electric power steering turned easily, with very little resistance. The engine came on with a noticeable rough-sounding grind whenever I hit the accelerator hard enough to need it. Otherwise I was able to cruise in stealth mode, using up the juice in the battery and replenishing it through judicious braking. The power meter's needle pointed in a green zone to indicate charging or in blue to suggest I might be burning a little gasoline.
One thing I quickly noticed was the car's willingness to coast. When I took my feet off the pedals, it was happy to roll on for an unexpected distance. Volkswagen designed the Jetta Hybrid to decouple its engine when coasting, what the Germans call sailing, to save fuel. Under these circumstances, the power meter showed it was still recharging the battery, albeit not as much as when I applied some brake pressure.
I missed any direct indication that I was driving under electric power in the Jetta Hybrid's instrumentation. Where theshowed a green EV icon when electrically propelled, this car offered nothing equivalent. The only indication was through watching the power flow animation on either the instrument cluster or the main LCD, which takes a little mental interpretation and so wasn't as safe as merely glancing down at an indicator light.
In E-mode, the car allows much greater acceleration under electric power than it does normally, while draining the battery pack much more quickly. I played with this mode in San Francisco, but found the engine had to step in when climbing an urban hill. The power flow animation showed the engine driving the front wheels, although the E-mode indicator remained on.
Most of my driving in this car involved a run from Los Angeles to San Francisco, so quite a bit of freeway driving at speeds of 70 mph. In Los Angeles traffic, the Jetta Hybrid showed its worth, seamlessly turning the engine on and off, and shifting through the transmission's seven gears very smoothly. In the stop-and-go, I noticed the trip meter averaging close to 45 mpg.
The freeway ride proved very comfortable, the Jetta Hybrid soaking up the bumps easily. Volkswagen replaced the torsion beam rear suspension of the standard Jetta with a multilink configuration for the hybrid version, making it better able to handle the load shifts associated with the extra weight of the battery pack. However, the suspension felt tuned mostly for comfort, as it leaned readily in turns.