16 MPG combined. That’s the fuel economy facing anyone considering the 2022 Mercedes-Benz AMG SL55 4matic Plus. It’s a number that might surprise a Prius driver, but for the target customer of this hand-built German performance roadster, it’s the price to pay for fast acceleration, luxury, and a strong presence. This isn’t a car for those prioritizing lower fuel costs; it’s a statement, a reward, a visceral experience that values thrills over miles per gallon.

City and highway performance

The EPA estimates reveal more detail. The SL55 gets 14 MPG in the city, reflecting stop-and-go traffic and immediate access to the engine’s power. On the highway, that figure improves to 21 MPG. While still not stellar, that highway number suggests the engine is relatively relaxed when cruising at steady speeds, although aggressive passing will reduce those gains. The strong torque of the 4.0L twin-turbo V8, combined with the responsive 9-speed automatic transmission, provides easy acceleration, but this responsiveness decreases fuel efficiency.

Annual fuel cost

According to the EPA, the estimated annual fuel cost for the 2022 Mercedes-Benz AMG SL55 is $3,600. This calculation is based on driving 15,000 miles per year, with an assumed even split between city and highway driving, and using the national average fuel price for premium gasoline, which this car requires. Individual fuel costs will vary depending on driving habits and local fuel prices. Drivers who frequently drive aggressively, or who live in areas with higher gas prices, can expect to exceed this annual estimate.

Real-world expectations

The EPA numbers provide a baseline, but real-world fuel economy often differs, especially with a car like the SL55. Its drivers probably aren’t focusing on fuel economy on their daily commutes. The temptation to enjoy the 469 horsepower and exciting exhaust note is too great. Expect numbers closer to the low teens in mixed driving if you frequently use the car’s performance. Relaxed highway cruising might approach the EPA’s 21 MPG figure, but fast acceleration and cornering will lower the MPG significantly. Fuel economy is likely a secondary concern for the typical SL55 buyer; the excitement of driving is more important. For more information, you can check all Mercedes Benz fuel economy data to understand the brand’s overall efficiency.

How it compares

The SL55 is unique in the performance roadster market, and its fuel economy shows that. A Porsche 911 Carrera S Cabriolet, a competitor, gets around 20 MPG combined with its turbocharged flat-six engine. The BMW M850i Convertible, another potential rival, delivers a similar 17 MPG combined. Even within Mercedes-Benz’s own lineup, the AMG GT Roadster is rated only slightly better, around 18 MPG combined, which highlights the trade-offs between performance and fuel efficiency. The SL buyer isn’t cross-shopping a Lexus hybrid; they’re comparing numbers among high-performance luxury vehicles, where fuel economy is often a compromise. Learn more about AMG MPG across all years to see how this model fares historically.

Tips to maximize efficiency

While fuel efficiency might not be a concern, there are ways to reduce the SL55’s gas usage. Use the available drive modes. Comfort mode softens the throttle response and optimizes the transmission for smoother, more economical driving, especially during commutes. Sport and Sport+ are better for fun drives when fuel consumption is less important.

Gentle acceleration and predicting traffic flow can improve fuel economy in city driving. Avoid quick starts and stops, allowing the car to coast when possible. The SL55’s powerful brakes are reliable, but reducing momentum saves energy and fuel.

Regularly check and maintain the tire pressure. Underinflated tires increase rolling resistance, which reduces fuel economy. See the sticker on the driver’s side doorjamb for the recommended tire pressure. Be sure to use the correct premium fuel as recommended by Mercedes Benz. Lower octane fuels could cause pre-detonation, making the engine compensate, which will decrease fuel economy.

Consider the weight you’re carrying. The SL55 is designed to handle and perform. The less weight it has, the less fuel it will use. Remove unnecessary cargo from the trunk. Although the car is designed to perform under a load, reducing the excess weight when you’re not using its full capacity will increase your overall fuel economy.