21 MPG combined won’t win any green awards, but it’s largely irrelevant to the buyer of a 2016 Audi S6 with the 4.0L V8. This isn’t a car purchased for getting good gas mileage; it’s a performance sedan draped in a cloak of luxury, designed to deliver power and understated elegance. The fuel economy is simply the price of admission to an exclusive club.

City and highway performance

The EPA estimates for the 2016 Audi S6 4.0L V8 are 18 MPG in the city and 27 MPG on the highway. The city figure reflects the engine’s thirst in stop-and-go traffic, where its 450 horsepower and twin turbochargers are largely unused. The highway number, however, shows a more efficient side to the S6. With its seven-speed automatic transmission finding the optimal gear ratio, and the engine running efficiently at highway speeds, respectable mileage can be achieved on longer journeys. A heavy foot will quickly diminish those gains.

Annual fuel cost

The EPA estimates that the annual fuel cost for the 2016 Audi S6 4.0L V8 will be $2,750. This figure is based on driving 15,000 miles per year and using the national average fuel prices at the time the estimate was calculated. Your actual fuel costs will vary depending on your driving habits, the type of fuel you use, and where you live, as regional fuel prices fluctuate. $2,750 gives you a good benchmark of what to expect to pay to feed this performance machine.

Real-world expectations

While the EPA figures provide a standardized benchmark, real-world fuel economy often differs. S6 owners report figures close to the EPA estimates, but aggressive driving can easily pull the combined MPG down into the mid-teens. It’s important to understand the S6’s nature: it encourages spirited driving. The instant surge of power, the refined exhaust note, and the surefootedness of the quattro all-wheel-drive system are intoxicating. Resisting the urge to exploit these attributes will be key to achieving anything close to the advertised mileage.

How it compares

The 2016 Audi S6 exists in a competitive segment of performance sedans. A comparable BMW 550i from the same year, with its 4.4L V8, achieves a similar 17 MPG city and 26 MPG highway. The Mercedes-Benz E550, boasting a 4.7L V8, lands around 18 MPG city and 25 MPG highway. These figures reveal that fuel economy differences are minimal within this class. Buyers are prioritizing performance and luxury over ultimate efficiency and the S6’s numbers are in line with what’s expected. For those seeking better mileage within the Audi family, examining S6 MPG across all years may reveal that newer or older models offer variations in fuel consumption. You can also compare all all Audi fuel economy data to see how it stacks up against other models.

Tips to maximize efficiency

Use a gentle acceleration style. The S6’s potent engine doesn’t require heavy throttle inputs for everyday driving. Gradual acceleration from a standstill and maintaining a steady speed will significantly reduce fuel consumption. Resist the urge to constantly dip into the turbocharger’s boost, as this is where the fuel economy plummets.

Use the Audi Drive Select system. Choosing the “Efficiency” mode optimizes various vehicle systems for maximum fuel economy. This mode adjusts the engine mapping, transmission shift points, and even the climate control system to minimize energy consumption. While it slightly dampens the car’s performance, it’s a worthwhile trade-off for increasing mileage on longer, less spirited drives.

Ensure proper tire inflation. Underinflated tires increase rolling resistance, forcing the engine to work harder and consume more fuel. Regularly check your tire pressure and maintain the recommended levels specified on the doorjamb sticker. This simple step can have a noticeable impact on fuel efficiency.

Minimize idling. Modern engines are designed to be turned off rather than left idling for extended periods. If you’re stopped for more than a minute, it’s generally more efficient to switch off the engine. Restarting consumes less fuel than idling and it reduces emissions.

Consider the fuel type. While the S6 can run on regular unleaded fuel, using premium gasoline as recommended by Audi will ensure optimal engine performance and efficiency. Premium fuel is designed to resist detonation in the engine’s high-compression cylinders, which can lead to slightly better fuel economy and power output.