Gas guzzlers are on the road to extinction

Michael Sivak and Brandon Schoettle explain that as recently as 2008, half the cars bought in America boasted fuel economy of less than 20 mpg -- the common definition of a "gas-guzzler". Today, guzzlers account for just 26 percent of new car sales. That's a steep drop in just seven years, and the percentage is likely to plummet far further over the next decade.

Why the change? There are at least four reasons:

Federal regulations: New EPA guidelines require all automakers doing business in America to meet a fleet-wide average fuel economy of 54.5 mpg by the year 2025. To hit that benchmark, automakers are phasing out gas-guzzlers and replacing them with more fuel-efficient rides.   

The high price of fuel: The past few months, U.S. drivers have enjoyed especially cheap gas, but the drop has been something of an anomaly. Prices at the pump are now climbing back toward "normal" territory, and depending on oil prices, drivers in some parts of the country could be paying nearly $4 a gallon before summer-blend gas arrives this spring. The high prices we've seen in recent years have been largely responsible for making fuel economy a top concern among auto shoppers. 

Hybrid and other technology: New technology is always pricey, and fuel-efficient tech is no exception. When hybrid cars debuted in the U.S. around the turn of the 21st century, they cost a pretty penny more than their gas-powered siblings.

Now, however, the hybrid price gap has narrowed, and many expect that electric cars (both standard and extended-range) will see a similar price drop soon -- especially if battery development projects like Tesla's gigafactory pan out. That's helping to draw more consumers to fuel-efficient rides. By 2017s, it's predicted that over half the vehicles sold in the U.S. will employ some kind of fuel-saving tech, from hybrid powertrains to turbochargers.  

Eco-friendly philosophy: Though it's hard to quantify, surveys have shown that increasing numbers of consumers are concerned about the environment. That sentiment is especially common among younger Americans. Fuel-efficient cars are very attractive to eco-friendly shoppers, who want their purchases to align with their ethics. 

To be sure, gas-guzzlers won't completely disappear -- at least not anytime soon. For example, heavy-duty vehicles aren't held to the same EPA standards as cars (a bone of contention with some foreign automakers), so automakers can continue making them for their commercial customers. Also, smaller luxury brands will probably find it easier to pay a federal penalty than make their high-end luxury rides comply with the new guidelines. But for better or worse, most folks on the road will enjoy more fuel-efficient vehicles in the years to come.

What we want to know is: when will 50 mpg be considered a gas-guzzler?