2007 Mercedes-Benz F700 Concept

2007 Mercedes-Benz F700 Concept

On the weekend, sometimes our mind wanders. Lately, it's been thinking about a big, graceful, German luxury sedan--that delivers the fuel economy of a Toyota Prius.

It doesn't exist yet, but Mercedes-Benz has a vision for how the company will build it. Their F700 concept car wowed the Frankfurt Motor Show in late 2007, and it's as relevant today as when they whipped off the covers 18 months ago. It shows that there's a lot of life left in the old internal combustion engine. You know, burning gasoline.

The key is a new type of combustion. Sure, the F700 is a gasoline-electric hybrid, but Daimler thinks gasoline engines will remain the centerpiece of the industry for decades to come. So the company decided to see how much improvement could be wrested from internal-combustion engines, whose core design now dates back 130 years. 

Their secret is a futuristic technology called HCCI, or homogeneous charge-compression ignition. This blends the low emissions of gasoline engines with the low fuel consumption and higher efficiency of diesel engines. Many carmakers have worked for years to make HCCI engines practical; among others, Volkswagen and General Motors have actual prototypes on the road.

The car introduced in Frankfurt was shocking because it was long, it was sleek--and it used only half as much fuel to give the same performance as the smallest 3.5-liter V6 now fitted to European models of the S-Class.  Fitted under its snub nose was a tiny 1.8-liter four-cylinder twin-turbo HCCI engine that burns regular gasoline.

It wasn't just the engine, of course. Like all good concepts, the styling was edgy--it was inspired by the shape of a dolphin cresting the waves--and the cabin was so extraordinarily long that rear passengers could stretch out to face each other in opposed seats.

We covered the F700 in much greater detail for a profile called "The Soul of a New Mercedes." Read it if you're intrigued.

But we'll leave you with this question: If the luxury and performance were the same, but the fuel consumption were much lower, would it still be an S-Class Mercedes if it had a tiny little four-cylinder engine?

2007 Mercedes-Benz F700 Concept

2007 Mercedes-Benz F700 Concept

2007 Mercedes-Benz F700 Concept

2007 Mercedes-Benz F700 Concept

2007 Mercedes-Benz F700 Concept

2007 Mercedes-Benz F700 Concept