Finding America’s Most Fuel-Efficient Automobiles

America's most fuel-efficient vehicle, the Toyota Prius.

The following story has been revised to include the Ford Fusion Hybrid in the Top 10 list.

If recent weeks are any indication, many American motorists are rethinking what to drive.  Last month’s sales numbers saw a spike in demand for small cars and hybrids (though there was also a bump in demand for pickups and bigger SUVs, despite rising fuel prices).

While there’s a law of diminishing returns, increasing your fuel economy from, say, 20 to 30 mpg can add up to savings of hundreds, even thousands of dollars a year, no wonder why so many motorists are thinking about downsizing or at least opting for alternative powertrains.

The good news is that you don’t necessarily need to switch to a battery car or hybrid to achieve big improvements in your fuel economy.  Nor do you need to swap that family van for a minicar.

True, vehicles relying on at least some form of battery power – whether hybrids, plug-ins or pure battery-electric vehicles – top the latest mileage charts, the latest crop of internal combustion engines are yielding respectable numbers – often at substantially lower sticker prices.

The gas-powered Hyundai Elantra delivers mileage that competes with some of the top hybrids.

Take the 2011 Hyundai Elantra.  With its inline-four-cylinder engine delivering a combined 33 mpg, the Korean compact is the eighth most fuel-efficient model on U.S. roads, according to data from the site TrueCar.com.  That puts it a full one mile per gallon ahead of the – admittedly one size-class larger – Toyota Camry Hybrid, which yields 32 mpg.  But the Elantra is, at $15,550, about $12,000 cheaper, in large part because it doesn’t carry around a dual drivetrain system.

Hybrids, nonetheless, dominate the chart, with the 49 mpg Toyota Prius at the top of the list, followed by the Lexus CT200h, a luxury version of the Japanese giant’s dedicated gas-electric model.  The Lexus version yields 41 mpg.

The majority of models in the battery-power list are Japanese, starting with Prius, the world’s best-selling hybrid.  There are three domestic models, the #4 Lincoln MKZ Hybrid and the Ford Fusion Hybrid, both sharing the same underlying gas-electric drivetrain, and the new Chevrolet Volt extended-range electric vehicle, rated at 37 mpg.

The figures are a bit misleading for Volt, however.  The new model is designed to yield an average of around 40 miles per charge, which GM estimates will satisfy the daily driving needs of about two-thirds of American motorists.  If the maker is right, Volt owners could go for extended periods without using any gasoline at all.

The chart (below), meanwhile, doesn’t include the new Nissan Leaf, a pure battery-electric vehicle, since it doesn’t use gasoline at all.  But using a complex formula to convert electric current to a gasoline equivalent, federal regulators  have assigned the Nissan battery car a rating of 99 MPGe, or miles per gallon-equivalent.

The chart for Top 10 battery-based vehicles covers models small and large, including the and Lexus RX400h hybrids.  (And if we had included a #11, it would’ve been the big Toyota Highlander Hybrid SUV.)

If you’re looking for maximum mileage on pure gasoline power, however, small is the way to go.  The list is limited to compact models or smaller.  The aforementioned Hyundai Elantra grabs the top spot, followed by the Mini Cooper Hardtop, at 33 and 32 mpg respectively.

Here, the Japanese are less dominant.  The best Toyota could land is third place, with the 31 mpg Yaris subcompact, and sixth-place Corolla, the compact offering rated at 30 mpg.  A third Japanese model comes from Mazda, the pint-sized Mazda yielding  31 mpg.

That Elantra leads a list of fuel-stingy Korean entries, four in all, at least if you count #9, the Korean-made, 30 mpg Chevy Aveo.  If you place that Chevrolet in the domestic column, Detroit gets two of the Top 10, with the Ford Fiesta rated fourth, at 31 mpg.

The sole European entries come from Mini, at #2 and #10.

As TheDetroitBureau.com previously reported, savings can add up quickly when you’re starting from a low base.  (Click Here for more.) Since the average American motorist clocks 15,000 miles annually, trading in a 20 mpg guzzler for a more efficient model, at 30 mpg, saves 250 gallons of gas annually.  At $4.00 a gallon, that would add up to $1,000 a year.

But going from 30 to 40 mpg yields significantly less savings, about 125 gallons, or just $500 annually.  So, while it pays to consider your options, it also makes sense to consider your needs before downsizing more than necessary.

Here are the most fuel-efficient vehicles in the U.S., broken down by battery-based and conventional drivetrains.

Hybrids:

Non-Hybrids:

Data Courtesy TrueCar.com.