We’re crawling, absolutely crawling on a stretch of highway just North of San Diego. This might be expected in Southern California during rush-hour, or any other time of day here for that matter, but the road is free of traffic. What we’re trying to do is win Hyundai’s Fuel Economy Challenge – an event organized as a part of the launch of the all-new 2011 Sonata.

This might not be an accurate representation of daily driving, but Hyundai is eager to show-off just how fuel efficient the new Sonata is. We manage to eek out a 46.8 mpg rating and as impressive as it sounds, that’s only enough for a 3rd place finish, with the winning team managing 52.8 mpg. We also just miss out on a private dinner with Hyundai Motor America CEO John Krafcik who promised just such a prize to anyone who could beat his 47.8 mpg score.

BEST-IN-CLASS FUEL ECONOMY

Under real world driving conditions you should expect closer to 22/35 mpg (24/35 with the six-speed manual). Those numbers are class-leading, topping even the Accord and Camry. They are also just one of many reasons why Hyundai’s new Sonata is a game changer, for the Korean automaker and for the conventionally conventional mid-size sedan segment.

Hyundai dedicated so much of the Sonata’s launch to driving home the fuel-economy numbers and we spent so much time competing in “eco challenges” that we needed to borrow the car the very next day just to get enough of a feel to give our first impressions.

DIRECT-INJECTION DELIVERS BIG JUMP IN POWER

So once again we’re out in the Sonata, but this time it’s different. The car’s new gasoline direct injection (GDI) 2.4-liter 4-cylinder isn’t just a fuel miser, it also makes 198-hp (200-hp in SE trim) and we’re using all of it.

Now this mid-size sedan is no blacktop burner, but acceleration is good, thanks in part to a significantly better power to weight ratio than the competition. This isn’t just because Hyundai’s 4-cyliner makes 22 more horsepower than an Accord, but because it weighs so much less than almost any other vehicle in its class. In fact, the Sonata is as much as 200-lbs lighter than some at just 3,199 lbs to start. A major reason for this is that Hyundai engineers didn’t need to design the chassis to handle a V6. That’s right, there won’t be a V6 option for the Sonata, but rather a turbocharged 4-cylinder that is set to arrive later this year. Game changer number two, or is that two and three?

The car’s new six-speed automatic transmission helps in both the fuel economy and performance arenas. Sick of playing catch-up with automakers like Honda and Toyota, in the past offering only 4-speed automatics while the Japanese had 5-speed units, Hyundai went and developed its own six-speed – a light weight compact unit that shifts seamlessly. A self-shifting feature is available for sportier driving, while the SE trim level gets paddle shifters.