What Counts as the Worst Gas Mileage Cars Ever
The worst gas mileage cars ever are vehicles that recorded the lowest combined city and highway miles per gallon in official EPA testing or real-world fleet data. These models span heavy trucks, large SUVs, and specialty vehicles where fuel efficiency was never the priority. Automakers publish fuel economy estimates, and regulators track which models fall far below average efficiency standards. The figures below reflect the latest publicly available EPA and manufacturer data.
EPA fuel economy labels list combined mpg, which blends city and highway driving. When a vehicle uses a large-displacement engine, all-wheel drive, or heavy frames, its combined mpg can drop sharply. In the worst cases, some trucks and SUVs return single-digit combined mpg, making them the least efficient mass-produced vehicles on sale. You can compare official estimates at the source for current and historical vehicle data.
Least Efficient Production Vehicles by Category
Full-Size Trucks and Heavy SUVs
Full-size trucks such as the Ford F-Series Super Duty and Chevrolet Silverado HD, when equipped with large V8 engines and four-wheel drive, often rank among the worst gas mileage cars ever in the truck segment. These models prioritize towing capacity and payload over efficiency, resulting in combined mpg figures that can fall below 15 mpg for the largest configurations. The EPA updates these estimates annually, and real-world towing can push consumption even higher.
Large luxury SUVs and extended-length models from brands like Cadillac, Lincoln, and Mercedes-Benz have also appeared on lists of the least efficient vehicles. Vehicles with V8 or V12 engines, heavy bodies, and all-wheel drive systems can return combined mpg in the low teens or lower. When these models are compared with smaller crossovers or sedans, the difference in fuel use is immediate and measurable.
Historical Models and Specialized Vehicles
Classic Muscle Cars and Large Sedans
Older muscle cars and full-size sedans from the 1970s and 1990s, such as certain big-block Chevrolet and Ford models, are often cited among the worst gas mileage cars ever when measured against modern standards. These vehicles used high-displacement engines with little emphasis on aerodynamics or lightweight construction, leading to combined mpg figures well below 15. EPA historical data allows direct comparison with today's models.
Specialty vehicles, including certain military-derived trucks and commercial vans with diesel or gasoline engines, can also rank at the bottom of efficiency tables. These vehicles are built for durability and load capacity, not fuel savings. When fleet managers or buyers prioritize utility over operating cost, these models remain in production or use despite their high fuel consumption.
How to Compare and Avoid the Worst Fuel Economy
Using Official EPA Data
The EPA's fuel economy website provides searchable lists where you can filter by vehicle class, make, and model to find the lowest combined mpg figures. You can compare any two vehicles side by side and see estimated annual fuel cost, greenhouse gas scores, and smog ratings. This tool is the most direct way to verify which current or past models are the worst gas mileage cars ever in a given category.
Before buying or leasing, check the window sticker or manufacturer specification sheet for the official combined mpg number. Real-world mileage can vary with driving style, payload, and terrain, but the EPA estimate remains the standard baseline. For broader context on fuel economy trends and regulations, you can review the Department of Transportation and EPA joint report on fuel economy trends.
For company-level data on how automakers are responding to efficiency standards, you can review the latest corporate average fuel economy reports published by the National Highway Traffic Safety Administration.