16 MPG combined. That’s the headline figure for the 2018 Mercedes-Benz AMG S65. But understanding that number requires understanding the car and the customer. This isn’t a vehicle aimed at the Prius-driving crowd. The S65 is a rolling expression of automotive indulgence, a leather-lined, technology-stuffed example of excess. The 6.0L V12 under the hood isn’t there for efficiency; it’s there to deliver a seemingly endless wave of perfectly smooth torque. Fuel economy is, at best, a tertiary concern for the type of buyer who puts an S65 in their driveway.

City and highway performance

The EPA estimates the S65 will achieve 13 MPG in the city and 22 MPG on the highway. That difference between city and highway figures is telling. The stop-and-go nature of city driving is where the V12’s thirst becomes most apparent. All that mass, coupled with aggressive acceleration, takes its toll. On the open road, however, with the transmission locked into a higher gear and the engine loafing along at lower RPMs, the S65 proves surprisingly capable of stretching a gallon. But even on the highway, remember this is a highly tuned AMG model; resist the urge to explore the upper reaches of its performance envelope, and your fuel consumption will suffer.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2018 Mercedes-Benz AMG S65 at $3,600. This figure is calculated based on driving 15,000 miles per year, with an assumed fuel price reflecting national averages. Keep in mind the S65 drinks premium fuel, which is always more expensive than regular unleaded. Also, that $3,600 figure represents a snapshot in time. Fluctuations in gasoline prices will directly impact your real-world costs. Aggressive driving, frequent short trips with cold starts, and substantial idling will also increase your annual fuel bill considerably.

Real-world expectations

The reality is, expect to see numbers lower than the EPA estimates in mixed driving. Achieving 22 MPG on the highway requires disciplined driving, something many S65 owners may find difficult to consistently maintain. A more realistic number for combined driving, factoring in a healthy dose of spirited acceleration, might be closer to 14-15 MPG. City driving could easily dip below 13 MPG, particularly in congested areas. This isn’t a car for hypermiling; it is a car for effortless performance, and that performance comes at a cost. People who buy this car are aware of this tradeoff.

How it compares

Compared to other high-performance luxury sedans, the S65’s fuel economy places it near the bottom of the pack. The V8-powered AMG S63, for example, manages a slightly better 17 MPG combined. Even the Bentley Flying Spur V8 achieves 15 MPG city and 24 MPG highway, a noticeable improvement. A BMW M760i xDrive, with its V12 engine, achieves 13 MPG city and 20 MPG highway. These comparisons matter, not because S65 buyers are particularly concerned with saving money on gas, but because fuel efficiency is often tied to overall engineering refinement. While the S65’s V12 is undeniably potent, more modern powerplants often offer a better balance of performance and economy. If you are curious, explore all Mercedes Benz fuel economy data.

Tips to maximize efficiency

While maximizing fuel economy might not be the top priority for an S65 owner, there are still steps that can be taken to minimize fuel consumption. First, resist the urge to constantly unleash the V12’s full potential. The engine’s prodigious torque output means you rarely need to dip deep into the throttle to maintain a brisk pace. Gentle acceleration off the line and smooth, gradual increases in speed will significantly reduce fuel consumption.

Second, pay attention to driving mode selections. The S65 offers various driving modes, including a Comfort mode that prioritizes fuel efficiency by optimizing throttle response and shift points. Using this mode during routine commutes can make a noticeable difference in fuel consumption. Avoid Sport and Sport+ modes unless you are actively seeking maximum performance.

Third, ensure that the tires are properly inflated. Under-inflated tires increase rolling resistance, which forces the engine to work harder and consume more fuel. Check the tire pressure regularly and inflate them to the manufacturer’s recommended specifications. Also, remember that this car’s massive wheels and tires are a drag on efficiency, literally and figuratively.

Fourth, minimize idling time. Modern engines consume a surprising amount of fuel while idling, even when stationary. Avoid unnecessary idling, especially during cold starts. If you anticipate a prolonged stop, consider turning off the engine. For other efficient AMG models, check out the AMG MPG across all years.