This is the car I covet:

And I don’t just want the new variant of the Volvo C30 because it’s oh so cute:
Called the C30 Efficiency, this special car will sip diesel fuel at the rate of 4.5L per every 100 kilometers. That’s 52.26 mpg to us Yanks. It achieves these numbers using a variety of techniques. For the engine, efficiency was increased by using low-friction transmission oil and optimizing the engine management software. An age old trick for good gas mileage, higher gearing, was used on 3rd, 4th and 5th gears to eek out a few more kilometers, as well. Low rolling resistance tires, another common strategy for higher mileage, were also used. Finally, Volvo made the C30 slipperier through the air by reducing its ride height, adding a special rear roof spoiler, new rear bumper, and even adding underbody panels to smooth out the car’s belly. Even the new 16-inch rims are aero-optimized!
The C30 Efficiency’s engine is a 1.6L turbodiesel producing 105 hp. Not only does it achieve 52.26 mpg, but it also emits less than 120g of CO2 per kilometer.
Hybrids and hydrogen fuel cells get all the press (and R&D dollars), but what we really need are some low-tech solutions that can increase fuel-efficiency right away. I only wish more car companies were interested in providing “efficient” variants of their car models. I’d certainly be willing to pay extra for a more efficient car, especially if I don’t have to spend several thousand extra dollars on a hybrid.