Let's get one thing straight: We do not hate green cars. We like green cars. We like diesel. We like weirdness and engineering genius. Which is why we decided to conduct a fuel-economy experiment with a heavy right foot.

While the 2007 Audi Q7 4.2 TDI admittedly lived at the higher end of the impossible-to-get-in- the-US diesel market, todays review subject is a far more attainable unattainable. The 2007 Honda Civic 2.2 i-CTDi doesn't just have a power train we all lust after—it's a platform we don't see in the domestic market. We're…