10 Cars with the Worst Fuel Economy
In the world of EPA-estimated fuel economy, the 1500-hp Bugatti Chiron Pur Sport gets 8 mpg in the city.
Most people scrolling through official government fuel economy numbers are looking for the big numbers that represent the most efficient vehicles. But once you've measured the best, you can also calculate the worst. And that's what we get from the Environmental Protection Agency's annual list of "Least Efficient Cars by EPA Size Class."
As you might suspect, high-performance sports cars and luxury rides dominate the rankings, with Rolls-Royce managing to claim an outsized portion of the top 10. But if you can afford one of these, you're probably not penny-pinching at the pump. The least expensive of these least-efficient cars starts at $30,295, but most cost hundreds of thousands of dollars.
There's room to argue about whether the EPA has correctly categorized these vehicles. Raise your hand if you think of the Ferrari GTC4Lusso as a minicompact. But the agency makes its own rules. Rather than fight, let's focus on just how inefficient some cars can be, and give Lamborghini bonus points for making the list with an engine that features cylinder deactivation and stop-start technology.
Mercedes-AMG GLA45 4Matic - 23 mpg (small station wagon)
We've ranked the Mercedes-Benz GLA-class as one of the best luxury subcompact crossovers sold today, and the AMG version is a far angrier bird. The GLA45 has been tuned by AMG, with the turbocharged inline-four boosted by nearly 150 horsepower to 382 horsepower, but this extra performance means sacrificing efficiency. Although the GLA45’s 23 miles per gallon combined may pale in comparison to some of the other numbers on this list, it still makes it the worst performing car in what the EPA considers part of the small station wagon category.
- Base price: $56,000
- Engine: 382-hp turbo 2.0-liter inline-4 engine, eight-speed dual-clutch automatic transmission
- EPA Fuel Economy combined/city/highway: 23/20/27 mpg
Bentley Continental GT and convertible - 15 mpg (subcompact)
Although the EPA categorizes the Bentley Continental as a subcompact, that label certainly doesn’t apply to its engine. You can get the Conti with a V-8, but it’s the 6.0-liter W-12 that lands the Continental GT on this list. Both the coupe and convertible variants get a combined 15 mpg, with the droptop one mpg worse off on the highway (19 compared to 20). With the turbocharged W-12 churning out 626 horsepower and 664 pound-feet and the Continental GT weighing more than 5000 pounds, the poor efficiency shouldn’t come as a surprise.
- Base price: $224,225
- Engine: 626-hp twin-turbo 6.0-liter W-12 engine, eight-speed dual-clutch automatic transmission
- EPA Fuel Economy combined/city/highway: 15/12/20 mpg
Rolls-Royce Cullinan – 14 mpg (mid-size station wagon)
Even if the EPA qualifies it as a mid-size station wagon, Rolls-Royce's entry into the SUV market is in line with the comfort and inefficiency ratings of its other models. The vehicle's weight, and the engineering it takes to isolate you from the outside world, are what help make a Rolls-Royce Cullinan a Cullinan. Burning so much fuel that we’re getting just 14 mpg combined? Didn't notice, thanks to double-paned windows and the two floors between us and the road. Now, let’s stand on the 563-hp, twin-turbo 6.7-liter V-12 and race to 60 mph in just 4.5 seconds. Thanks.
- Base price: $335,350
- Engine: 563-hp twin-turbo 6.7-liter V-12 engine, eight-speed automatic transmission
- EPA Fuel Economy: 14/12/20 mpg
Rolls-Royce Phantom and Phantom EWB – 14 mpg (large sedan)
The Rolls-Royce Phantom was engineered to make the road disappear. We've said before that riding in a Phantom is like levitating, thanks in part to the vehicle's air suspension and a camera that spots potholes to adjust that suspension. The transmission is tuned to keep the engine humming at low rpm, which enhances the quiet feel. But all of that floating comfort—and the 563-hp twin-turbo V-12 that moves the Phantom along— comes at the expense of fuel economy. While you could manage 20 mpg on the highway in one of these things, the 14 mpg combined figure is in line with the rest of the Rolls-Royce entries on the EPA's list of shame.
- Base price: $457,750
- Engine: 563-hp twin-turbo 6.7-liter V-12 engine, eight-speed automatic transmission
- EPA Fuel Economy combined/city/highway: 14/12/20 mpg
Rolls-Royce Ghost and Ghost EWB - 14 mpg (large)
For 2021 Rolls-Royce introduced an all-new Ghost, now riding on Rolls’ own Architecture of Luxury instead of borrowing a platform from the BMW 7-series like the pervious generation. Some things haven’t changed, though—the Ghost still packs a 6.7-liter V-12 under the hood and weighs more than 5500 pounds, contributing its dismal fuel economy. While highway miles per gallon went up by one to 19 mpg in the new model, the combined rating remains at 14 mpg. At least Ghost owners can lounge in the spacious and opulent backseat while the hired help refills the tank.
- Base price: $314, 400
- Engine: 563-hp twin-turbo 6.7-liter V-12 engine, eight-speed automatic transmission
- EPA Fuel Economy combined/city/highway: 14/12/19 mpg
Rolls-Royce Wraith – 14 mpg (mid-size)
Thanks to a 624-hp version of the Rolls-Royce Ghost's V-12 engine (guess what’s next on the list?) and a shorter wheelbase than the Ghost, the Wraith handles better than the sedan on which it’s based. That, plus all of the luxury and personalization options that come with a Rolls-Royce means you’ll be comfortable as the car burns through fuel. As with the Dawn—and, in fact, all of the Rolls-Royces on this year's list—the Wraith gets 14 mpg combined, whether it's you or your chauffeur doing the driving.
- Base price: $343,350
- Engine: 624-hp twin-turbo 6.7-liter V-12 engine, eight-speed automatic transmission
- EPA Fuel Economy combined/city/highway: 14/12/18 mpg
Rolls-Royce Dawn – 14 mpg (compact)
The next Rolls-Royce on the EPA's list is the 563-hp Dawn, a luxurious four-seat convertible that packs plenty of driver-assistance features alongside its gas-guzzling performance numbers. The Dawn can go from zero-to-60 mph in 4.3 seconds but keeps its focus on comfort. The eight-speed automatic transmission, for example, can use GPS information to change where it shifts gears based on whether the car is going uphill, downhill, or around corners. That’s proof Rolls-Royce has plenty of interesting and helpful technology at its disposal, but the company's engineers are not prioritizing fuel economy in any way.
- Base price: $359,250
- Engine: 563-hp twin-turbo 6.7-liter V-12 engine, eight-speed automatic transmission
- EPA Fuel Economy combined/city/highway: 14/12/18 mpg
Ford Mustang Shelby GT500 – 14 mpg (subcompact)
Finally, a sort-of affordable fuel burner. The Ford Mustang Shelby GT500 starts at $73,095, which isn't terrible for what Ford calls the "most powerful and fastest Mustang of all time." That means going from zero-to-60 mph in 3.4 seconds thanks to a total of 760 horsepower and 625 lb-ft of torque. Don't worry, you can still spend $18,500 on the Carbon Fiber Track package, $10,000 for painted racing stripes and other features to tip the price into the six-figure range, but you can't improve upon the measly 14 mpg. That cobra logo is going to cost you, one way or the other.
- Base price: $74,095
- Engine: 760-hp supercharged 5.2-liter V-8 engine, seven-speed dual-clutch automatic transmission
- EPA Fuel Economy combined/city/highway: 14/12/18 mpg
Lamborghini Aventador coupe and roadster – 10 mpg (two-seater)
While the combined mpg rating for Lamborghini's flagship Aventador (in both coupe and roadster versions) is the same as the Chiron, the Lamborghinis are 2 miles per gallon better on the highway (15 versus 13). But you don't get 730 horsepower and 509 lb-ft of torque from a small, fuel-efficient engine, and that's what the Aventador offers in its unmistakable wedge-like body. You can get more power from the SVJ version, but the EPA does not offer breakout fuel-economy numbers for the variants. At least the Italians built cylinder deactivation and stop-start technology into the V-12, otherwise the numbers would probably be worse.
- Base price: $421,321
- Engine: 730-hp 6.5-liter V-12 engine, seven-speed automated manual transmission
- EPA Fuel Economy combined/city/highway: 10/8–9/15 mpg
Bugatti Chiron Pur Sport - 10 mpg (two-seater)
Last year, the “base” Bugatti Chiron tied for the absolute worst fuel economy of all 2020 vehicles with just 11 miles per gallon. Unsurprisingly, sticking a giant wing on the rear decklid to create the track-focused Chiron Pur Sport has led to a car with even worse fuel economy. But the Chiron Pur Sport is now tied for the worst gas mileage among 2021 vehicles with 10 mpg, and the EPA says that Pur Sport owners will spend $9.45 to drive just 25 miles. Plus the $3.6 million price tag for the car itself, so whatever. You buy a Chiron for the 9.4-second quarter-mile time and W-16 engine, not for its fuel economy.
- Base price: $3,600,000
- Engine: 1500-hp quad-turbo 8.0-liter W-16 engine, seven-speed dual-clutch automatic transmission
- EPA Fuel Economy combined/city/highway: 10/8/13 mpg
Sebastian Blanco has been writing about electric vehicles, hybrids, and hydrogen cars since 2006. His articles and car reviews have appeared in the New York Times, Automotive News, Reuters, SAE, Autoblog, InsideEVs, Trucks.com, Car Talk, and other outlets. His first green-car media event was the launch of the Tesla Roadster, and since then he has been tracking the shift away from gasoline-powered vehicles and discovering the new technology's importance not just for the auto industry, but for the world as a whole. Throw in the recent shift to autonomous vehicles, and there are more interesting changes happening now than most people can wrap their heads around. You can find him on Twitter or, on good days, behind the wheel of a new EV.
Caleb Miller began blogging about cars at 13 years old, and he realized his dream of writing for a car magazine after graduating from Carnegie Mellon University and joining the Car and Driver team. He loves quirky and obscure autos, aiming to one day own something bizarre like a Nissan S-Cargo, and is an avid motorsports fan.
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