Milking a Bull: Automakers eek out extra fuel economy on older models

Conspiracy theorists have long insisted that automakers could push their vehicles to achieve better fuel economy, and as it turns out, they were right. Of course, it isn't as easy as flipping a magic MPG switch, but automakers are making incremental gains on vehicles even between redesigns. Techniques like changing gear ratios, lowering revs at highway speed and using lower rolling resistance tires are helping drive up efficiency a few percentage points at a time.

For example, the 2009 Cobalt XFE (above) achieves 37 mpg on the highway compared to 36 mpg for the 2008 model with minimal aero and mechanical changes. Ford made similar changes to the 2009 Escape, enabling the Blue Oval's smallest crossover to hit 28 mpg in 2WD four-banger guise. Honda achieved similar incremental improvements when it introduced cylinder deactivation on the 2008 Odyssey. Chrysler will show 1 mpg improvement on the 2009 Avenger and Sebring four-cylinder model, which will bring the Pentastar's midsize sedans to 31 mpg.

While everyone seems to be sitting on the car buying sidelines until some unbelievably fuel efficient vehicle comes along with great looks and a low price tag, the reality is that these baby steps are what we should expect. There are some some bigger jumps on the horizon, like the Chevy Cruze that promises 45 mpg on the highway and diesel offerings like the Jetta TDI and oil-burning Accord. For the next few years, however, expect automakers to pick the low hanging fruit of high gas mileage first.