One of those is fuel economy. With ratings of up to 35 mpg highway for the standard Sonata, it's one of the best picks out there. But those who are really green can do even better: the 2011 Hyundai Sonata Hybrid. And gas mileage is even better in the Sonata Hybrid—an EPA-rated 35 mpg city, 40 highway.
The Sonata Hybrid is not only Hyundai's first U.S.-sold hybrid; it also includes all-new lithium-polymer battery technology, which has been co-developed with LG Chem. Hyundai has opted for a conventional six-speed automatic transmission over the complex planetary setups that other some other automakers have offered in their hybrids. There are two electric motors in the system, with one that decouples the gasoline engine, allowing it to run on battery power at higher speeds in some situations when cruising or coasting; otherwise, just as in other hybrids, the electric motors can assist the engine or help recharge the battery pack.
Overall, the system isn't quite as seamless as those units from Ford and Toyota; it's a little lumpier in its transitions, which some will notice, but the Sonata Hybrid can run in electric mode at higher speeds than any other affordable hybrid—we saw more than 70 mph without the gasoline engine running, at one point.
Hybrid Sonata models don't look that much different. Sheetmetal is the same, and there's the same roomy interior, but the front and rear details have changed a bit and it nets the Hybrid some significant aerodynamic improvements.
For more information on everything else regarding the 2011 Hyundai Sonata Hybrid package—including styling, comfort, safety, and features, all of which are comparable to that of the standard Sonata versions—see our full review on the 2011 Hyundai Sonata.