15 MPG combined is a figure most car buyers would run screaming from, but for the 2015 Mercedes-Benz S65 AMG, it’s simply what you must accept. You don’t buy a V12-powered land yacht like this expecting Prius-like efficiency. You buy it for effortless power, supreme luxury, and the subtle flex that only a twin-turbocharged twelve-cylinder engine can provide. The S65 AMG caters to a very specific clientele: those who prioritize performance and exclusivity above all else, and for whom fuel costs are a negligible concern.

City and highway performance

The EPA estimates for the 2015 S65 AMG break down to 13 MPG in the city and 20 MPG on the highway. The stark difference reflects the fuel-hungry nature of a large displacement, turbocharged engine working hard to move a heavy car through stop-and-go traffic. On the open road, with the engine cruising and the aerodynamics working in its favor, the S65 can stretch a gallon of premium unleaded a bit further, though “efficient” is hardly the operative word. Expect to see the fuel gauge drop noticeably with every hard acceleration, a characteristic baked into the DNA of any AMG product.

Annual fuel cost

According to the EPA, the estimated annual fuel cost for the 2015 Mercedes-Benz S65 AMG is $3,850. This figure is based on driving 15,000 miles per year and using national average fuel prices. Keep in mind that the S65 requires premium fuel, which is typically more expensive than regular gasoline. This also assumes a specific ratio of city to highway driving; those who spend more time in congested urban environments can expect to exceed this estimate significantly. While $3,850 per year is a substantial sum for fuel, prospective S65 AMG owners are likely more concerned with the car’s six-figure price tag and the cost of maintaining such a complex, high-performance machine.

Real-world expectations

While the EPA figures offer a baseline, real-world fuel economy for the S65 AMG can vary considerably depending on driving style and conditions. A lead foot will undoubtedly result in lower numbers, while a more relaxed approach, particularly on long highway journeys, might yield slightly better results. Don’t expect miracles, though. Considering the engine’s output and the car’s weight, achieving anything significantly better than the EPA estimates is unlikely. Owners trading up from other AMG models might find these numbers broadly in line with their previous experience, while those new to the AMG fold should brace themselves for more frequent trips to the gas station.

How it compares

The S65 AMG occupies a rarified space in the automotive world, but there are a few potential competitors to consider. The Audi S8, for example, offers a similar blend of performance and luxury, but with a more fuel-efficient twin-turbo V8 and an EPA combined rating of 19 MPG. The BMW 760i, also powered by a V12, achieves a similar 17 MPG combined rating. Even the Porsche Panamera Turbo S, with its monstrous twin-turbo V8, manages a slightly better 18 MPG combined. These differences, while seemingly small, translate to hundreds of dollars in annual fuel cost savings. However, for the S65 buyer, the allure of the AMG-tuned V12 often outweighs the marginal gains in efficiency offered by its rivals. For more general information, see all Mercedes Benz fuel economy data.

Tips to maximize efficiency

While “fuel efficiency” and “S65 AMG” are not typically used in the same sentence, there are a few techniques to minimize fuel consumption. Avoid aggressive acceleration and hard braking. The S65’s immense power reserves make it tempting to unleash its full potential at every opportunity, but a smoother, more deliberate driving style will noticeably improve fuel economy. Use the car’s cruise control system on the highway to maintain a consistent speed and minimize unnecessary throttle inputs.

Ensure that the tires are properly inflated to the recommended pressure. Underinflated tires increase rolling resistance, forcing the engine to work harder and consume more fuel. Check the tire pressure regularly and adjust as needed. Even small differences in pressure can affect fuel economy.

Reduce unnecessary weight in the car. Removing items from the trunk and passenger compartment can lighten the load, improving fuel economy slightly. While this effect may be minimal in a car as heavy as the S65, every little bit helps.

Consider using the car’s “Comfort” or “Eco” driving modes, if equipped. These modes typically tone down the engine’s throttle response and adjust the transmission’s shift points to prioritize fuel efficiency over outright performance. The difference will be noticeable behind the wheel. Also research S65 MPG across all years.