It sounds like simple economics, because it is: If the cost of running your car increases, you're going to either use it less--not an option for some--or find a cheaper option.

February vehicle sales rose by 15.7 percent last month, and many of those were for more compact and fuel-efficient vehicles, in light of rising gasoline prices. Compact, efficient cars are also becoming more desirable on the used market as gas prices rise.

According to The Detroit News, that's the highest since February 2008, just before the housing market collapse brought the car industry with it.

Chrysler was the biggest winner, with sales up 40.4 percent on February 2011, and one of its biggest sellers was the comparatively gas-saving Chrysler 200 sedan.

Ford has seen a 14.3 percent year-on-year increase, with many of its sales attributed to EcoBoost models, and the efficient Ford Focus--not surprising when gasoline increased by around 35 cents per gallon from February 2011 to February 2012.

GM's rise has been slower at only 1.1 percent, and Toyota, which majors on efficiency, gained 12.4 percent. Analysts also attribute some of these gains to the unusually mild February weather.

Of course, not all efficient vehicles sold well this February--in our monthly look at electric vehicle sales, Nissan sold 29 percent fewer Leafs than it did in January. More positive were Chevy Volt sales - up from 603 in January to 1,023.

As gas prices rise and more electric vehicles hit the market, we might even see those numbers creep up further--but for the time being, it's the regular, inexpensive cars that are proving more popular.

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