18 MPG combined is what you get for driving Audi’s flagship sedan with its strong 4.0L V8. This isn’t a Prius for taking the kids to school. It’s a long-wheelbase luxury car designed for easy long-distance travel and keeping its occupants comfortable. The A8 L focuses on a refined driving experience and advanced technology over getting the best fuel economy, appealing to executives and owners who value performance and prestige.

City and highway performance

The A8 L’s fuel economy breaks down to 15 MPG in the city and 23 MPG on the highway. The city figure shows the demands of stop-and-go traffic and the engine’s work to move the car’s weight. The highway number is a better sign of its ability to cruise. The V8’s large torque allows for relaxed driving at higher speeds, and the automatic transmission manages gear changes well to improve efficiency when possible. A lighter foot will produce better results, but restraint isn’t always easy in a car that accelerates so effortlessly.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2020 Audi A8 L 4.0L V8 at $3,200. This is based on driving 15,000 miles per year, with a mix of city and highway driving, and using national average fuel prices. This is just an estimate though. What you actually spend will vary depending on your driving, local fuel prices, and the type of fuel used. Premium fuel is recommended (if not required) for best performance, which raises the expense.

Real-world expectations

The EPA estimates provide a benchmark, but real-world fuel economy is rarely the same. Drivers who often accelerate quickly or spend a lot of time in city traffic will likely see numbers lower than the official ratings. However, those who focus on fuel efficiency on long highway trips might achieve slightly better results. Watch the A8 L’s trip computer and adjust your driving to potentially extend time between fill-ups. See A8 MPG across all years.

How it compares

There are fuel economy differences among large luxury sedans. The BMW 750i xDrive, also with a V8, offers similar performance and gets similar fuel economy, around 17 MPG combined. The Mercedes-Benz S560, another competitor, is about the same. A V12 engine in the S600 (if you can find one) will cause fuel economy to drop. Hybrid options from Lexus (LS 500h) offer much better fuel efficiency, around 25 MPG combined, but they don’t have the power and driving engagement of the V8-powered Audi. For those prioritizing fuel efficiency within the Audi family, exploring all Audi fuel economy data might show more economical options, but with less power and luxury.

Tips to maximize efficiency

The Audi A8 L has various drive modes. “Efficiency” mode adjusts engine and transmission settings for the best possible fuel economy. It may slightly reduce throttle response, but for everyday driving, it can noticeably reduce fuel consumption.

Make sure the tires are properly inflated. Underinflated tires increase rolling resistance, making the engine work harder. Check the tire pressure regularly and inflate to the recommended level, found on the doorjamb sticker.

Avoid aggressive acceleration and braking. Smooth inputs minimize fuel wastage. Anticipate traffic flow and maintain a consistent speed when possible. This improves fuel economy and enhances the driving experience.

Reduce weight. Excess cargo in the trunk adds to the vehicle’s weight, hurting fuel economy. Remove any items that aren’t essential to minimize the load on the engine.

Consider using the start/stop system in city traffic. This system automatically shuts off the engine at idle to save fuel. If you find the system intrusive, you can disable it, but be mindful of its fuel-saving benefits during frequent stops.