America’s 5 Worst MPG Cars By Size Class

While elite carmakers are moving toward hybridization to improve mpg and cut greenhouse gases, there remain many exceptions with gas-guzzling internal combustion engines.

Actually, the majority of powerful-to-extremely powerful supercars and luxury vehicles are unencumbered with electrified propulsion – not counting Tesla’s vehicles, which alone avoid petroleum entirely.

As the culture and market push back against some eco technologies, as recently as 2012 it was shown there were twice as many 500-horsepower models sold In America as hybrid models, let alone the still-new crop of plug-ins.

In defense of the truly top-end expressions of traditional automotive art, it’s been said supercars aren’t often driven to their potential or even very far per year – thus it’s less relevant if some get under 2 mpg at full tilt, because that’s the exception, not the rule.

To be fair also, if you flog a Tesla Model S to its full potential, it also will consume far more kilowatt-hours per hundred miles than the EPA certifies – so any way you slice it there is no free energy consumption lunch.

That said, petroleum-powered “lunch” does cost more, and as Top Gear showed in a 2009 video just before major manufacturer EVs came on the scene, when driven hard, supercars might get between 1.7-5 mpg, without even guessing what the emissions were.

“There you go, the sound of the 20th century,” said former Top Gear host Jeremy Clarkson as he raced around a track. The video from the folks who allegedly rigged a Tesla Roadster run-out-of-juice scene highlights some of the attitudes that prevail among traditional car lovers.

Plug-in electrified vehicles this decade have faced a society that today – thanks to reduced gas prices – is buying an increased percentage of trucks, SUVs, and crossovers as hybrids are 1.85 percent of the market and plug-in cars make up 0.72 percent

Perhaps the new 200-mile EVs starting with the Chevy Bolt and Tesla Model 3 will help? On the high-end, plug-in hybrids and EVs are coming from the makers of today’s guzzlers, but wheels turn slowly – and usually just fast enough to keep automakers’ fleet average close to in compliance with global regulations.

The U.S. Environmental Protection Agency observes various classes of vehicle by interior volume as having the worst mpg in the United States. Obviously their ironic inside measurements belie larger exterior dimensions, but in any case these classifications are what the EPA says, and we’ll list them below. The EPA figures its annual numbers based on 15,000 miles traveled consisting of 45 percent highway driving, and 55 percent city.

Subcompact: Bentley Continental GT Convertible – 15 mpg


A perfect car for Rodeo Drive, or taking a care-free road trip is Bentley’s opulently equipped convertible Continental positioned for the “Grand Touring” (GT) segment.

The stylish vehicle starts at about $218,000 and is fited with a 6.0-liter W-12 engine delivering 582 finely pureed horsepower and 531 pounds-feet of torque.

This is enough to get the heavyweight subcompact class car up to 60 mph in around 5 seconds, with top speed of about 195 mph.

Fuel economy by EPA reckoning is 15 mpg combined, or 6.7 gallons per 100 miles. City mpg is 12 mpg, and it gets 20 mpg on the highway – actually not shabby. Tailpipe emissions is 604 grams per mile.

As a point of comparison to the opposite side of the automotive spectrum, a Toyota Prius gets 170 grams mile, a Chevy Volt is rated 51 grams per mile, and a Tesla Model S is rated 0 grams per mile.

Annually, the EPA says in 15,000 miles, the Bentley Continental GT guzzles 22 barrels of petroleum; the Prius drinks 6.3 gallons, the Volt responsibly sips 2.0 gallons and as you might have guessed, the Tesla doesn’t consume petroleum.

Minicompact: Aston Martin DB9 GT – 15 mpg


Sshhh. Don’t tell James Bond he drives a car the federal government classes by interior volume as a “minicompact.”

Then again, the gorgeous Aston does have a few things going for it that tip the perception scale in its favor.

Priced from just below $200,000 up to $235,000 for the limited James Bond edition, the most powerful DB9 ever built is motivated by a hand-assembled 6.0-liter V12 serving up 540 horses and 457 pounds-feet of torque.

Zero to 60 mph takes 4.4 seconds and top speed is 183 mph.

No wonder the Fusion is considered attractive.

No wonder the Fusion is considered attractive.

On the EPA cycle, its combined 15 mpg equals 6.7 gallons per 100 miles. Its city mpg is 13, its highway is 19 – about the same as a full-size pickup truck, but considerably more swank in the eyes of most. Tailpipe emissions is 587 grams per mile.

Dominating the front visage is the sizable grille copied and replicated by Ford on so many of its cars. Aston has sued Henrik Fisker for allegedly diluting its brand image but a four-door Ford Fusion does at least a passing resemblance to the lines of a two-door car suited for 007 – but you’ll save a lot of money, if not appearing nearly so cool.

Compact: Rolls Royce Phantom – 14 mpg


Perfect for that aspiring rap star after earning a first couple million dollars, or a member of the global elite, the Rolls Royce Phantom comes in a coupe and four-door and both are tied for least efficient compact-class car.

Unlike other compacts, this one is priced a wee-bit higher from $418,000, and instead of the usual four-banger under the hood, propulsion is provided by a more appropriate 6.7-liter 12-cylinder.

The 5,840-pound car is as you would expect luxuriantly appointed throughout and while its interior is compact, exterior dimensions are on order with a large car.

Fuel economy is rated at 14 mpg or 7.1 gallons per 100 miles. It also returns 11 mpg city, and a not-too-bad 19 mpg highway. Tailpipe emissions are 638 grams per mile, and oil consumption is 23.5 barrels per year.

Midsize: Ferrari FF – 13 mpg


Ferrari’s FF benefits this year from a mid-cycle refresh granting more power, revised styling and a wider range of powertrains to choose from.

It is the model with 6.3-liter V12 that makes our list, and not the turbocharged V8 powerplant borrowed from the California T.

Around 700 horses are expected to be generated by this model that’s not yet featured on Ferrari’s website, and to cost around $300,000.

As listed on the EPA’s website, the 13 mpg combined car is rated also at 7.7 gallons per 100 miles, or 11 mpg city, 16 mpg highway. Tailpipe emissions are 697 grams CO2 per mile, and annual petroleum sipping comes to 25.4 barrels.

A version also is available with stop/start technology, but the EPA says it gets the exact same efficiency rating.

Two-Seater: Lamborghini Aventador 12 mpg

Aventador SV.

Aventador SV.

High on the fantasy list for web-surfing office workers, and priced within reach of a successful Wall Street broker is the Lamborghini’s none-too-shy Aventador.

Stickering from just below $400,000 to just below $550,000, the car makes do with a 6.5-liter V12 churning 691 horsepower, 507 pounds-feet of torque. The 750-4 SV gets about 50 more horsepower.

Funneling that power to the wheels is a 7-speed ISR automatic transmission, and this machine is meant to giddy-up-and-go.

Restrained to chill-out model on the law-abiding EPA cycle, the 12 mpg vehicle is rated for 8.3 gallons per 100 miles, or 10 mpg city, 17 mpg highway. Tailpipe CO2 is 727 grams per mile.