23 MPG combined isn’t going to win any hypermiling awards, but it’s respectable for the 2023 Mercedes-Benz AMG SL43. This isn’t a dedicated economy car; it’s a luxurious and sporty roadster designed for spirited driving and open-air thrills. Drivers considering the SL43 prioritize performance and prestige over outright fuel savings, but appreciate that it doesn’t completely obliterate their fuel budget. The SL43 caters to a specific buyer: those who want a stylish, engaging driving experience without sacrificing modern efficiency entirely.

City and highway performance

The AMG SL43’s EPA ratings break down to 21 MPG in the city and 27 MPG on the highway. The city figure reflects the stop-and-go nature of urban driving, where the small-displacement engine works harder to overcome inertia. The highway MPG is where the SL43 shines a bit more.

The 9-speed automatic transmission allows the engine to settle into a more efficient cruising mode, making longer journeys more palatable for both your ears and your wallet. This split in fuel economy underscores the car’s dual nature: it’s capable of enjoyable city trips while still being suited for weekend getaways. The highway MPG emphasizes the benefits of its advanced engine technology and aerodynamic design for extended cruising.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2023 Mercedes-Benz AMG SL43 at $2,500. This calculation is based on driving 15,000 miles per year, using a blend of city and highway driving (55% city / 45% highway), and using the EPA’s projection for the national average fuel price. This figure gives a straightforward view of the yearly expense associated with fueling the SL43. While the actual cost can vary based on driving style and local fuel prices, it provides a good benchmark for buyers considering the long-term ownership costs of this performance roadster.

Drivers who drive a lot less than 15,000 miles per year will clearly spend less, while those with a heavier foot may see that $2,500 figure climb.

Real-world expectations

While the EPA estimates provide a useful baseline, real-world fuel economy for the AMG SL43 is likely to fluctuate based on driving habits and conditions. Drivers who frequently engage the sportier driving modes and enjoy the turbocharger’s boost will undoubtedly see a dip in MPG. Conversely, those who adopt a more conservative driving style, using the car’s comfort settings and gentle acceleration, may come closer to, or even slightly exceed, the EPA ratings.

Factors like traffic congestion, weather conditions, and even tire pressure can also impact fuel efficiency. It’s a safe bet to expect figures somewhere between 19 MPG and 29 MPG, depending on how enthusiastically the SL43 is driven. The turbocharged engine and refined transmission do their best, but ultimately this is a performance machine, not a Prius.

How it compares

Compared to its competitors, the AMG SL43 sits in an interesting spot. The Porsche 718 Boxster, in its base 2.0L configuration, achieves around 24 MPG combined, putting it slightly ahead. The BMW Z4 M40i, with its more powerful inline-six engine, gets around 25 MPG combined. However, the SL43 offers a unique blend of open-top luxury and AMG performance that neither of those vehicles quite matches. Stepping up within the SL range to the SL55 or SL63 will see fuel economy drop significantly, down into the high teens. While someone looking at all Mercedes Benz fuel economy data might see better MPG figures elsewhere in the lineup, no other model captures the essence of the SL like the SL43 does with its blend of efficiency and performance. It represents a conscious trade-off: drivers accept slightly lower MPG than some alternatives in exchange for the cachet, technology, and driving experience of an AMG-tuned Mercedes-Benz roadster. Consider AMG MPG across all years; the SL43 represents a relative high watermark for efficiency.

Tips to maximize efficiency

Take advantage of the SL43’s driving modes. Selecting “Comfort” or “Eco” modes will optimize the engine and transmission for fuel efficiency, softening throttle response and encouraging earlier upshifts. This is especially effective during city driving where aggressive acceleration is less necessary. Experiment with different modes to find the right balance between performance and economy for your daily commute.

Monitor your tire pressure diligently. Properly inflated tires reduce rolling resistance, which directly improves fuel economy. Check your tire pressure regularly and ensure it matches the recommended levels listed on the doorjamb sticker. This simple task can make a noticeable difference over time.

Anticipate traffic flow to avoid unnecessary braking and acceleration. Smooth and consistent driving is key to maximizing fuel efficiency with any vehicle, but especially those with turbocharged engines. By maintaining a safe following distance and anticipating traffic changes, you can minimize fuel-wasting stop-and-go driving.

Avoid unnecessary idling. Modern engines are designed to be efficient, and idling consumes fuel without covering any distance. If you’re stopped for more than a minute or two, it’s generally better to turn off the engine. The SL43’s start/stop system can assist with this in many situations.