18 MPG combined is the price of admission to the exclusive club of ultra-luxury performance sedans, and the 2023 Audi S8 4.0L 8-cyl demands that toll without apology. This isn’t a car for penny-pinchers or hypermilers; it’s for successful executives, entrepreneurs, and enthusiasts who prioritize effortless power and opulent comfort above all else. They understand that a twin-turbocharged V8 delivering prodigious thrust simply won’t sip fuel like a hybrid hatchback.

City and highway performance

The EPA estimates the S8 achieves 15 MPG in the city and 23 MPG on the highway. While those numbers might seem disheartening compared to more efficiency-focused vehicles, they’re fairly representative of what to expect from a car with this level of performance and refinement. The city figure reflects the engine’s thirst during stop-and-go traffic, while the highway number shows it can achieve decent efficiency when cruising at a constant speed. Remember, this car boasts 563 horsepower and can rocket from 0 to 60 mph in under 4 seconds. That kind of performance requires fuel, and the all-wheel-drive system also contributes to the fuel consumption, constantly adjusting power delivery for optimal handling and grip.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2023 Audi S8 at exactly $3,200. This figure is based on driving 15,000 miles per year, with 55% of those miles driven in the city and 45% on the highway. It further assumes a national average fuel price, which fluctuates, meaning your actual fuel costs may vary depending on your driving habits and where you live.

Real-world expectations

While the EPA provides a standardized benchmark, real-world fuel economy can differ significantly based on driving style, traffic conditions, and even weather. An S8 driver who frequently enjoys the car’s performance capabilities will likely see numbers below the EPA estimates. Conversely, someone who primarily uses the car for long highway commutes and exercises restraint might achieve slightly better fuel economy. Factors such as tire pressure, vehicle maintenance, and the use of accessories like air conditioning can also subtly influence fuel consumption. Aggressive driving will always result in a steeper fuel bill given the S8’s performance potential.

How it compares

The Audi S8 occupies a segment where fuel economy isn’t the primary concern, but understanding the competitive landscape is still relevant. The Mercedes-Benz S580, with its twin-turbo V8, achieves a similar 16 MPG city, 25 MPG highway. The BMW 760i xDrive, also packing a powerful V8, lands at around 18 MPG city and 25 MPG highway. The Porsche Panamera Turbo S offers comparable performance but typically delivers similar or slightly worse fuel economy.

When you look at all Audi fuel economy data, it’s clear the S8 trades efficiency for uncompromised performance. Buyers considering the S8 are typically less focused on maximizing MPG and more interested in comparing performance metrics, luxury features, and brand prestige. They might review S8 MPG across all years, but it is unlikely to deter them.

Tips to maximize efficiency

While the S8 isn’t designed for hypermiling, there are still ways to minimize its fuel consumption. Gentle acceleration and avoiding hard braking can significantly reduce fuel usage, especially in city driving. The S8’s powerful engine responds eagerly to throttle inputs, so a light foot can make a noticeable difference.

Using the Audi Drive Select system can also help. Selecting the “Efficiency” mode optimizes various vehicle settings, such as throttle response and transmission behavior, to prioritize fuel conservation. While it might slightly dampen the car’s performance, it’s a worthwhile option for situations where fuel economy is important.

Regular maintenance, including ensuring proper tire inflation and timely oil changes, is critical for maintaining optimal fuel efficiency. Low tire pressure increases rolling resistance, forcing the engine to work harder. Similarly, old or degraded oil can reduce engine efficiency, leading to increased fuel consumption.

Minimize idling whenever possible. Modern engines consume a surprising amount of fuel while idling, especially when cold. If you anticipate being stationary for more than a minute or two, it’s best to shut off the engine.