Mercedes C250 BlueEfficiency gets 45 mpg

The gamut of models spanned by the Mercedes C-class just got a little wider. On one end, you have the CNET Editors' Choice C63 AMG, a rip snorting beast with a 405 horsepower 6.2-liter V-8 that chugs gasoline at a rate of 16.2 mpg. Way down on the other end is the newly announced C250 CDI BlueEfficiency Prime Edition, a 204 horsepower four-cylinder that gingerly sips diesel at a rate of 45 mpg. It's hard to believe these two vehicles are cut from the same cloth, but they are.

The heart of the C250 is Mercedes' new 2.2-liter BlueEfficiency engine, which uses direct injection technology and a dual stage supercharger to achieve its stellar 45 mpg fuel economy and clean emissions. Mercedes plans to replace its current four-cylinder diesel offering with the BlueEfficiency and place the new engine in the E-Class, in the new GLK-Class and in the future E Class Coupe.

While the C63 does 0-60 mph in about the time it takes to say "C250 CDI BlueEfficiency Prime Edition", the C250 takes a more lethargic seven seconds. Where the C63 sports a beefy aero package with multiple vents and power-bulges, the C250 has airflow-enhancing exterior-mirror housings and smooth underbody cladding. Instead of wide sticky rubber, the C250 has efficient low rolling resistance tires.

In the cabin, the C250 CDI BlueEfficiency Prime Edition gets a six speed manual transmission with overdrive and a new gearshift and fuel-efficiency display in the instrument cluster to help the driver better pilot the efficient four-banger to high miles per gallon bliss.

Mercedes only plans to make and sell 5,000 of the Prime Edition of the C250 CDI BlueEfficiency. Sure, comparing the C63 with the C250 CDI BlueEfficiency Prime Edition is pretty silly, but in these times of rising fuel costs, it's hard to argue that mpg may be the new mph.