If you're short on cash for gas, these are not the right vehicles for you.
The US Department of Energy has a total of 2,067 models and model derivatives listed in its fuel economy database. Minor changes to power outputs and body styles have an effect on economy figures. While at one end of the spectrum, the Hyundai Ioniq Electric is rated the most economical vehicle in the US at 136 MPGe, there are many that are way off the mark. We've done some searching to find the 10 thirstiest vehicles on sale in the US. Needless to say, if you're digging through your car seats to find change for gas at the end of the month, these are not the right vehicles for you.
At number ten on this list - making it the most economical vehicle here - the Mercedes-Benz G550 isn't much of a surprise. Its boxy design and heavy duty construction both scream 'thirsty', and at the luxurious end of Mercedes' spectrum it carries a big thirsty engine to boot, too. Powered by Mercedes' 4.0-liter twin-turbo V8, it outputs 416 horsepower and 450 lb-ft of torque. Power is channeled to all four wheels via a seven-speed automatic gearbox, with a low-speed transfer case on offer for hardcore off-roading. The result is 13 mpg combined, broken down to 13 mpg in the city and 14 mpg on the highway.
Consuming 12 miles per gallon in the city, the Ferrari GTC4Lusso only earns a 'decent' economy rating due to its 17 mpg highway rating. That makes it marginally better for day-to-day use than the G550, but at a combined 13 mpg, it's still thirsty. Of course, as a pinnacle sports car, no one buys a GTC4Lusso for economy. What you do buy it for is the 6.3-liter naturally aspirated V12 under its hood, kicking out 680 horsepower and 514 lb-ft of torque and driving all four wheels via a trick dual-gearbox system. But with space for four passengers, a 0-60 mph time of 3.1 seconds, and the soundtrack of a Ferrari V12, 13 mpg seems a small price to pay.
Surprisingly, there are just two Ferraris on this list. What isn't surprising is that both of them feature V12 engines and immense performance. The Ferrari 812 Superfast may offer the same combined consumption rating as the GTC4Lusso mentioned above, but it bags a spot higher on this list as it is 1 mpg less economical on the highway. But those who buy an 812 Superfast couldn't care less when they've got a 789-hp V12 under the hood displacing 6.5 liters and powering the rear wheels exclusively. The 812 Superfast is the current halo model in Ferrari's production lineup, and while it's strictly a GT car, the performance it offers – 0-60 mph in 2.8 seconds and 0-124 mph in 7.9 – places it firmly in supercar territory.
You can have the most economical engine around, but if the car you're driving has the aerodynamic properties of a brick wall, then you're not going to get very far on a full tank of fuel. But when you're driving a Mercedes-AMG G63, you have neither aerodynamic prowess nor an economical engine, as its 5.5-liter bi-turbo V8 gets pretty thirsty when it's pumping out 563 horsepower to all four wheels. 13 mpg is the claimed average you'll get, breaking down to 12 mpg in the city and 15 on the highway. According to the government, it'll cost you $12,000 more in fuel over five years than if you were to drive an 'average new car'.
The most attainable car on this list is the Jeep Grand Cherokee Trackhawk. It's also one of the most perversely pleasing ones on this list; after all, who can resist the idea of Dodge Hellcat power in a family SUV? But it's a far cry from the family model it's based on when it comes to fuel economy, as feeding 707 horses from a supercharged 6.2-liter V8 takes more than just a few drops of gas. With city consumption of 11 mpg and highway driving yielding 17 mpg, the average economy of 13 mpg seems fair – especially when the Trackhawk will demolish the 0-60 mph sprint in 3.5 seconds on its way to an 11.6-second quarter mile.
The Pagani Huayra is the successor to the seemingly immortal Zonda, defining the hypercar segment with its unique design, attention to detail, and high-quality materials. You've just got to take one look at that dash design to know this is something special. However, something tells me that when Horacio Pagani designed the Huayra and equipped it with a 700-horsepower 6.0-liter AMG V12 wearing two turbos, he didn't have economy in mind. The US government concurs, and the Huayra carries Trackhawk-matching economy figures of 11 mpg in the city and 17 mpg on the highway, with a combined score of 13 mpg.
With two lesser model derivatives already on this list, were you really expecting the Mercedes-AMG G65 not to make an appearance somewhere higher up? Well, at number four on the list, the Mercedes-AMG G65 is rated at 12 mpg, 11 in the city and 13 on the freeway. The boxy dimensions and all-wheel drive don't help matters much, but what secures the G65's slot with some of the most atrocious economy figures around is the engine under its hood. As part of the '65' grouping of vehicles from Mercedes-AMG, it carries the family V12, a bi-turbocharged 6.0-liter unit with 621 horsepower and a monumental 738 lb-ft of torque.
Lamborghini's own V12 makes an appearance at number three on this list. Though both the Aventador S Coupe and Roadster boast claimed average consumption figures of 12 mpg, the roadster is actually marginally lighter on juice with 16 mpg on highways compared to the coupe's 17-mpg figure. No matter which body style you choose, the mid-mounted 6.5-liter naturally aspirated V12 outputs the same 730 horsepower and 509 lb-ft of torque, sent to all wheels via an automated single-clutch gearbox. Zero to 60 mph takes 2.9 seconds for the coupe, which makes those thirsty figures a little more bearable – as does the glorious V12 noise.
Four out of the ten vehicles on this list are Mercedes models. More than that, all of them are variants of the G-Class, which speaks volumes as to the fact that economy is not what it's built for. But at 11 mpg combined, city, and highway, the G550 4x4-squared is the heaviest of the lot. But what makes it so heavy compared to its brethren? Well, the G550 4x4-squared is the extreme off-road version of the G-Class. It may utilize the same 416-hp 4.0-liter bi-turbo V8 as the standard G550, but Mercedes enhances its capabilities off-road by outfitting it with portal axles, 22-inch wheels, three lockable differentials, and 325/55 profile tires. Who cares about the economy when you can quite literally go anywhere?
The thirstiest vehicle on sale in the United States, ladies and gentlemen, is the Bugatti Chiron! It's no wonder, really, when it's powered by a quad-turbo, 8-liter W16 engine making 1500 horsepower. It's one of the world's most powerful production cars, and arguably the ultimate in grand touring luxury. It's not just about straight line pace, but the ease with which the Chiron does it. The efficiency figures, though, are a little concerning (probably not for buyers that can shell out the $3 million it takes to buy one) – 9 mpg in the city, and just 14 mpg on the highway for a combined figure of 11. Makes sense then that if you own a Chiron, you likely own an oil field too.