16 MPG combined. Let’s be clear: nobody buys a 2021 Audi S8 for its fuel economy. This is a fact, not a criticism. The S8 is a 563-horsepower missile cloaked in executive sedan clothing, and demanding Prius-like efficiency would betray its mission. The person signing the check for this car prioritizes effortless speed, a meticulously crafted interior, and understated presence over trips to the gas station. Understanding the S8’s fuel consumption is simply understanding its place in the automotive landscape.

City and highway performance

The EPA estimates the S8 will achieve 13 MPG in the city and 22 MPG on the highway. The difference between these figures reveals the engine’s character. Around town, stop-and-go traffic and the car’s substantial weight work against efficiency. The twin-turbo V8 needs a heavy foot to get moving, and doing so hurts fuel consumption. However, out on the open road, the S8’s cylinder deactivation system and well-spaced eight-speed automatic transmission allow it to cruise more efficiently. The highway figure suggests that longer journeys, while still consuming a considerable amount of fuel, won’t be quite as painful at the pump.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2021 Audi S8 at $3,600. This calculation is based on driving 15,000 miles per year, with 45% of those miles driven in the city and 55% on the highway. It also assumes national average fuel prices. Owners should understand that this is merely an estimate. Aggressive driving, living in an area with higher fuel costs, or exceeding the average annual mileage will all significantly increase this figure. For context, $3,600 represents a large amount of money, roughly equivalent to a premium vacation or a significant home repair.

Real-world expectations

Forget the EPA numbers. In the real world, expect even lower figures if you regularly exploit the S8’s performance potential. The temptation to unleash the V8’s fury is ever-present, and resisting that urge will be a constant battle. Conversely, those who spend most of their time on relatively flat highways and resist the urge to accelerate vigorously may see numbers closer to the EPA’s estimate. Overall, it’s wise to budget for fuel costs considerably higher than the EPA’s projections.

How it compares

The S8 exists in a rarified segment where fuel economy isn’t a primary concern. But even among its peers, it sits near the bottom of the efficiency rankings. The Mercedes-AMG S63 Sedan, with its own 4.0L twin-turbo V8, achieves a slightly better 17 MPG combined. Even the V12-powered BMW M760i, despite its larger displacement and two extra cylinders, posts similar numbers thanks to advanced efficiency technologies. The Porsche Panamera Turbo, another direct competitor, handily beats the S8 with its 18 MPG combined. These minor differences might not sway a buyer at this price point, but for those even slightly concerned with fuel consumption, other alternatives exist.

Tips to maximize efficiency

Despite its performance credentials, there are ways to improve fuel economy in the S8, though miracles aren’t possible. Use the “Efficiency” driving mode whenever appropriate. This setting dulls throttle response and optimizes transmission mapping for fuel conservation. It will make the car feel less responsive, but it can yield a noticeable improvement on longer highway drives.

Gentle acceleration and anticipatory driving are key. Avoid hard launches and abrupt braking. Coasting to red lights or anticipating traffic flow can reduce fuel consumption without sacrificing too much time. The S8’s adaptive cruise control, when used responsibly, can also contribute to a smoother, more efficient driving style.

Ensure proper tire inflation. Underinflated tires increase rolling resistance, which forces the engine to work harder and consume more fuel. Check your tire pressures regularly and maintain them at the recommended levels, which can be found on a sticker inside the driver’s doorjamb.

Minimize unnecessary weight. Carrying around extra cargo in the trunk or backseat adds weight, which negatively impacts fuel economy. Remove any items that are not essential for your journey. Every little bit helps, even if it seems insignificant for a car this powerful.

Consider the long-term benefits of regular maintenance. Keeping the engine properly tuned, replacing air filters when necessary, and using the recommended oil can all help give you optimal fuel efficiency. These preventative measures might seem minor, but they can prevent larger problems down the road and help maintain the S8’s performance and efficiency.

Discover all Audi fuel economy data or see S8 MPG across all years.