When it comes to hybrid cars, I think people really care about one simple test: Does the car deliver on its mileage promises in the real world?

And when it comes to the new Mercedes S400 BlueHybrid I took on a trip from New York City to Pennsylvania's Pocono Raceway last week, the happy answer is that this luxury hybrid sedan actually beats its EPA ratings of 19 mpg city/26 mpg highway. During the drive to the International Motor Press Association Test Days (which brought nearly 150 new cars and trucks together for testing on public streets and Pocono’s road-racing course), the Benz delivered a stellar 29 mpg on the highway and 21 mpg during city testing; that’s also roughly one-third better mileage than the 15 mpg city/22 mpg highway I logged in the gas-only V8 S550 version of the same Mercedes. And while the hybrid Mercedes -- with the V6 engine and an ultracompact lithium-ion battery -- isn’t as fast as the 382-horse V8 model, its 295 horsepower was plenty to get the big S-Class rolling and to pass the slowpokes in my way.

Innovations like a true luxury hybrid -- an oxymoron only several years ago -- such as the S400, in addition to the glorious array of cars at the Test Days event, got me thinking. First, it seems to me that the experts who predicted that carmakers would dramatically scale back their offerings because of the recession are likely on the wrong track. From upscale Hyundais to luxury hybrids, from modern diesels to newfangled luxe hatchbacks like the Porsche Panamera and the BMW 5-Series GT, more style and powertrain permutations were on display than ever. Second, seeing the Benz hybrid alongside the hyperpowered Mercedes AMG models, and the BMW's 1-Series diesel cozying up to the insane 555-horsepower BMW X5M and X6M crossovers, drove home the challenges that automakers face in trying to keep everyone happy.

So while regulations might decree that cars average 35 mpg by 2016, and while even many luxury- and sports-car buyers are starting to expect better fuel economy, cars will never be one-size-fits-all. There's no better place to see this than at Pocono Raceway, where every year carmakers truck an auto show's worth of vehicles in for the event, and where the badass BMW crossover that draws dirty looks from some sparks longing gazes in others.