Hyundai’s corporate work ethic and frugality have resulted in a strong emphasis on developing and manufacturing key components in-house. By avoiding the hybrid technology used in the Sonata Hybrid’s chief competitors-the Ford Fusion, the Nissan Altima, and the Toyota Camry-the company has smartly dodged the licensing fees of patented technology and tapped existing hardware for its first gasoline/electric car.
The homebrew hybrid
Primary propulsion for the hybrid Sonata comes from a 2.4-liter four-cylinder that’s now running the Atkinson cycle and is tuned for fuel economy, resulting in a 169-hp output. Assistance is provided by a 40-hp electric motor mounted in place of the torque converter inside Hyundai’s six-speed automatic transmission. At 209 hp and 195 lb-ft of torque, total output is slightly higher than the base Sonata’s. In electric-only operation, a clutch between the engine and the motor disconnects the two power sources to eliminate the drag of the engine’s spinning internals. A second, smaller electric motor restarts the engine from red lights or in stop-and-go traffic.
Hyundai uses the electric motor, in lieu of a torque converter, to dampen shift shock, an arrangement that works quite well. The Sonata climbs through its six gears seamlessly, with reasonable speed. On kickdown, though, gear changes feel slower the harder you squeeze the throttle. Off the line, the low-end torque of the electric motor transitions linearly to the engine’s high-rpm thrust. When pushed, the Sonata Hybrid feels quicker than the factory’s reported 0-to-62-mph run of 9.2 seconds.
Hyundai claims a top electric speed of 62 mph, but getting there under electric power alone from a stop is impossible. Our technique for maximum efficiency is to use the gas engine to accelerate up to city or suburban speeds and then massage the throttle to coax the car into electric mode. City fuel economy, at 37 mpg, falls 4 mpg short of the Fusion Hybrid’s. But, at an estimated 40 mpg on the highway, the Sonata will claim the best EPA highway mileage among its hybrid mid-size sedan competitors.
The Sonata will be the first production hybrid to store electricity in a lithium-polymer battery. Laminating the anode, polymer separator, and cathode together in a li-poly battery means that there’s no need for a rigid structural casing, which saves weight and allows for more flexible packaging. In theory, these prismatic cells should be cheaper to manufacture than cylindrical cell, lithium-ion batteries. Reality, however, says that the supply base for Hyundai’s battery is quite small and, for the time being, will command a premium from supplier LG Chem. We’re still waiting to hear the official price of the car, but we expect the Sonata Hybrid to match its competitors at roughly $27,000, even if Hyundai has to sell each car at a small loss.
Same inside, fresh outside
The trunk-mounted battery pack drops cargo capacity from 16.4 to 10.7 cubic feet, but the rear seatbacks still fold down for long items. From the driver’s seat, this is the same Sonata that debuted earlier this year, with the exception of unique interior colors and relevant hybrid displays on the instrument cluster and the navigation screen. To establish its presence as a green alternative, the hybrid trades the base Sonata’s fussy chrome grille for a thin ornamental slit and a gaping hexagonal lower grille. There are also new headlights, clear taillights, altered rocker panels, different wheels, and a fresh rear fascia. The changes also have a functional role; they significantly lower the aerodynamic drag coefficient from 0.29 to 0.25.
A hybrid that’s comfortably familiar
Although it may not have the cachet of hybrid-only styling like a Toyota Prius, the Sonata’s normalcy is a good thing-especially when it comes to driving. The gas/electric Hyundai provides the mechanical ebbs and tides of rpm, torque, and engine growl as the gears change. With that character, the Sonata joins the ranks of the Porsche Cayenne and the Honda CR-Z as hybrids that are enjoyable- even fun-to drive.