10 thirsty performance cars, and a BMW M5 at 14 mpg burns $5,850 a year in fuel

Performance cars deliver speed, but the fuel bill that comes with it is rarely small, and the numbers can surprise even enthusiasts. Federal ratings and 2027 data show which models drink the most, from big sedans to compact coupes. Here are ten performance cars that rank among the thirstiest on sale.

1. BMW M5: Fuel Bill Champion

2027 fuel economy rankings put the M5 Sedan at 14 mpg combined, the lowest figure among the mainstream performance cars in this group. At that rating, annual fuel spending reaches $5,850, the largest bill on the list and a number that dwarfs the cost of running an ordinary family sedan.

Buyers drawn to the twin-turbocharged power should treat fuel as a major line item alongside insurance and tires. Short trips and spirited driving push real-world costs toward the rating’s worst case, so budgeting for premium fuel at roughly that annual figure is the safer assumption.

2. Chevrolet Corvette Z06: Mid-Engine Thirst

mpgbuddy’s 2027 ranking lists the Corvette Z06 at 15 mpg combined, with an estimated $5,500 a year in fuel. That is only one mile per gallon better than the M5, despite the Z06 being a two-seat sports car rather than a large, heavy sedan.

The result shows that low weight does not offset a high-revving, high-output engine when the throttle is used freely. Owners who track the car or drive it hard should expect consumption to sit at or beyond the combined rating, and fuel costs to follow.

3. Cadillac CT5-V: Midsize Sedan Outlier

fueleconomy.gov’s 2026 worst-of lists name the CT5-V the least efficient midsize car of the model year, at 15 mpg combined. Most rivals in the same size class return far better numbers, which makes the Cadillac stand out as a performance trim rather than a typical commuter.

Shoppers cross-shopping the V against standard midsize sedans should weigh the penalty at the pump each week. For anyone covering long daily distances, the extra fuel spending can eventually rival a meaningful share of the monthly payment.

4. Mercedes-AMG GT: Grand Touring Gulp

2027 gas guzzler data rates the AMG GT 63 4matic+ coupe at 16 mpg combined, which works out to about $5,150 a year in fuel. The all-wheel-drive grand tourer carries a heavy twin-turbo V8 and a large body, both of which weigh on its efficiency.

Anyone considering the coupe as a daily driver should factor in a fuel budget above $5,000 annually. The rating comes from a single trim, so lesser AMG GT variants may differ, but the 63 shows what the top version demands.

5. Mercedes-AMG SL: Roadster Penalty

federal fuel economy listings name the AMG SL55 and SL63 the least efficient minicompact cars of 2026, each rated at 16 mpg combined. The convertible’s classification as a minicompact puts it in a group of small, mostly sporty vehicles where that figure still lands at the very bottom.

The open-top luxury roadster pairs grand-touring comfort with turbocharged V8 output, and the mileage reflects that appetite. Owners planning cross-country drives should expect frequent stops, and the lower rating applies to both power levels equally.

6. Audi RS 6 Avant: Wagon Without Mercy

the government’s 2026 rankings list the RS 6 Avant as the least efficient midsize station wagon of the model year, at 16 mpg combined. The long-roof Audi pairs a family-hauling cargo area with supercar-adjacent performance, which explains the weak number.

Buyers attracted by the practicality of a wagon should recognize that the cargo space comes with a hefty fuel habit. Compared with ordinary wagons and crossovers, the Audi asks for noticeably more money at every fill-up, and the penalty compounds across years of ownership. Anyone treating the RS 6 as a family hauler should budget accordingly.

7. Ford Mustang Dark Horse: Pony Car Cost

fueleconomy.gov’s worst-of tables place the Mustang Dark Horse at the bottom of the 2026 subcompact class, rated 17 mpg combined. Ford’s track-focused trim uses a naturally aspirated V8, and the rating shows what that engine costs in everyday driving.

The Dark Horse remains one of the more affordable ways to own a V8 coupe, yet the lower purchase price does not fix the thirst. Drivers comparing it with the standard Mustang should expect a visible gap in annual fuel spending. The subcompact label can mislead, since small size here brings no efficiency advantage.

8. BMW M3: Compact Sedan Cost

mpgbuddy’s M3 Sedan listing shows the 2027 model at 19 mpg combined, with 16 mpg in the city and 23 on the highway. Premium fuel is required, and estimated annual spending comes to $4,350.

The M3 ties for the most efficient entry on this list, yet its figures still trail ordinary sedans by a wide margin. Highway cruising helps, but heavy city use drags results toward the 16 mpg figure and raises the yearly total. Even the best case in this group costs thousands of dollars annually.

9. BMW M2: Small Coupe Appetite

mpgbuddy’s M2 Coupe page lists the 2027 car at 19 mpg combined, split between 16 mpg in the city and 23 on the highway. Premium fuel is specified, and the yearly cost is estimated at $4,350.

The M2 matches the larger M3 on every efficiency number despite being the smaller and lighter car. Buyers expecting compact dimensions to deliver savings should recognize that the engine, not the footprint, drives the bill. Shoppers choosing between the two can treat fuel cost as a tie and decide on size, price and seating.

10. Nissan Z: Nismo Fuel Habit

2027 least efficient cars list rates the Z NISMO at 19 mpg combined and estimates annual fuel spending at $4,350. The most track-oriented Z trades some efficiency for extra output and tuning, landing at the same rating as the BMW M cars.

Among rear-drive sports coupes the Z remains relatively accessible, but the NISMO trim pushes running costs higher. Buyers should compare the rating with a standard Z, which can reduce the yearly total without losing the car’s character. The shared 19 mpg figure also places it level with the smaller BMW coupes.

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