The 2015 Mercedes-Benz SLK55 AMG, with its hand-built 5.5L V8, achieves a combined fuel economy of 22 MPG. This figure is almost secondary to the visceral experience it delivers. This isn’t a car bought by drivers looking for lower fuel costs; it’s for drivers who prioritize the sound, the fury, and the sheer thrill of a naturally aspirated AMG engine over saving a few dollars at the pump. They understand the trade-off, and they happily accept it. The SLK55 AMG is about emotion, not economy.

City and highway performance

The EPA estimates the SLK55 AMG will achieve 19 MPG in the city and 28 MPG on the highway. The city figure reflects the engine’s willingness to deliver instant power, often resulting in enthusiastic acceleration and less-than-gentle driving habits. On the open road, however, the 7-speed automatic transmission helps to manage fuel consumption at cruising speeds, allowing for a respectable 28 MPG when driven with restraint. These numbers are important, but they don’t tell the whole story of how this car feels in each driving scenario. The city MPG is a consequence of an exuberant spirit, while the highway MPG is a reward for responsible touring.

Annual fuel cost

According to the EPA, the estimated annual fuel cost for the 2015 Mercedes-Benz SLK55 AMG is $2,650. This calculation is based on driving 15,000 miles per year and fuel prices averaging those found nationally. Variables such as your individual driving style, the type of fuel used (premium is recommended), and local fuel costs will impact the final figure. Consider this number a benchmark; drivers with lead feet or significantly longer commutes will likely exceed it, while those who carefully manage their driving habits might see slightly lower costs.

Real-world expectations

While the EPA figures provide a baseline, most SLK55 AMG owners report fuel economy figures that vary slightly depending on driving habits and locale. Owners who primarily drive in congested city environments might find their average closer to the 19 MPG city rating. Those who do mostly highway driving may see numbers closer to, or even slightly exceeding, the 28 MPG highway rating. Aggressive driving, particularly frequent use of the throttle to experience the engine’s power, will invariably bring the average down. Consulting owner forums can provide a broader view of all Mercedes Benz fuel economy data based on diverse driving experiences.

How it compares

In terms of fuel economy, the SLK55 AMG wasn’t aiming to lead its class. Consider the contemporary Porsche Boxster S (with its naturally aspirated flat-six), it achieved around 20 MPG combined. The BMW Z4 sDrive35i (turbocharged inline-six) also hovered around the same 20 MPG mark. Each car offers varying degrees of performance and driving character. The SLK55’s relatively thirsty V8 is the price you pay for its distinctive soundtrack and potent power delivery, which differs markedly from the turbocharged options. Exploring SLK55 MPG across all years reveals a consistent theme: Performance comes first, efficiency second.

Tips to maximize efficiency

Smooth acceleration and braking are critical. Avoid sudden bursts of speed and anticipate traffic flow to minimize harsh stops. The SLK55’s powerful engine is responsive to even the slightest throttle input, so a gentle foot can significantly improve fuel consumption. The AMG Speedshift transmission offers different driving modes; experiment with “C” (Controlled Efficiency) mode for relaxed cruising and improved fuel economy compared to “S” (Sport) or “M” (Manual) modes.

Ensure your tires are properly inflated to the pressure recommended on the door jamb. Under-inflated tires increase rolling resistance, wasting fuel and affecting handling. This is especially important on a performance car like the SLK55 AMG, where precise handling is a key part of the driving experience.

Reduce unnecessary weight inside the car. Extra cargo adds to the overall load, requiring more energy to accelerate and maintain speed. Keeping the trunk clear of unnecessary items contributes to optimal fuel efficiency and preserves the car’s agile feel.

Regular maintenance is essential for peak performance and fuel economy. Ensure the engine is properly tuned, the air filter is clean, and the spark plugs are in good condition. A well-maintained engine operates more efficiently, saving fuel and prolonging the life of the vehicle.