Those eagerly looking forward to our next hybrid family sedan comparison have to wait just a bit longer -- this Hyundai Sonata Hybrid we recently tested is a pre-production model.
To start, Hyundai slightly revised its estimated fuel economy numbers for the Sonata Hybrid to 36/40 city/highway mpg -- down 1 city and up 1 highway. Against the likes of the Ford Fusion Hybrid and Toyota Camry Hybrid, the highway number is right at the top of the class. Then there's range. Given the Sonata Hybrid's 17.2-gallon tank, you could theoretically roll more than 680 highway miles between fill-ups. Vacationing families and business road warriors will enjoy blowing past all those gas pumps.

Improved fuel economy obviously doesn't materialize out of thin air. Hyundai's Direct Hybrid Blue Drive system earns its keep as a full parallel setup with an actual step-ratio automatic transmission, a departure from the continuously variable transmissions common in most hybrids. But the Sonata Hybrid's six-speed automatic is missing one key ingredient: a torque converter. In its place is the keystone of this hybrid's operation: an electric traction motor rated at 40 horsepower and 151 pound-feet of torque.
Because the motor is synced directly to the transmission, a clutch latches to and unlatches from the gasoline-fed 2.4-liter inline-four with 166 horsepower and 154 pound-feet of torque on tap (also revised slightly from earlier in the year). As you'd expect from a hybrid, the Atkinson-cycle variant from Hyundai's Theta II family has been optimized for maximum efficiency. Final combined performance figures are 206 horsepower and 193 pound-feet of torque.

Acceleration is far from astonishing, with a 0-to-60 mph blast taking 9 seconds and the quarter mile 16.8 seconds at 84.2 mph. The Sonata has to draw power from both the engine and the 1.4-kilowatt-hour lithium-polymer battery pack to reach those numbers. Why lithium-polymer and not lithium-ion? Hyundai says the chemistry helps lower overall hybrid system weight (the pack is just 96 pounds), and its configuration allows for more cargo space because of its forward-trunk-mounted position. The system's driving modes -- full electric, engine only, hybrid with electric power assist, and hybrid with battery charging -- are dependent upon driver input.