21 MPG combined. That’s the fuel economy for buyers who want the performance and open-air driving of the 2015 Audi S5 Cabriolet. People buy this car for its responsive supercharged V6, all-wheel drive, and top-down experience. Fuel consumption is a pragmatic concern, a price paid to experience this Audi.

City and highway performance

The S5 Cabriolet’s EPA ratings place it in the middle for fuel efficiency for performance convertibles. The 18 MPG city rating reflects the engine’s power, even at low speeds, and stop-and-go traffic increases gas consumption. The 26 MPG highway number is possible with a light foot and cruise control, showing the engine’s efficiency when not accelerating. The seven-speed S tronic dual-clutch transmission helps, providing quick shifts and maintaining engine speeds for performance and fuel savings.

Annual fuel cost

Based on EPA estimates, the annual fuel cost for the 2015 Audi S5 Cabriolet is $2,750. This is based on driving 15,000 miles per year and using the national average fuel price for premium gasoline, the fuel recommended for this vehicle. This cost is a benchmark, but real-world costs can change based on driving habits, local fuel prices, and annual mileage.

Real-world expectations

S5 Cabriolet owners often report MPG figures that differ from EPA estimates. City driving in heavy traffic congestion can result in fuel economy below 18 MPG. Long highway trips at a steady speed might yield numbers closer to, or slightly exceeding, 26 MPG. Driving style affects fuel consumption; aggressive driving, with hard acceleration and braking, will decrease MPG. Even with spirited driving, many owners find the combined MPG around the EPA estimate, accepting the fuel cost for the performance.

How it compares

The S5 Cabriolet competes with other performance convertibles. For example, a BMW 435i Convertible with the inline-6 turbo offers similar performance to the Audi, but with a slightly better 23 MPG combined. A Mercedes-Benz C400 offers similar power and luxury with a slightly lower 22 MPG combined. See all Audi fuel economy data for more information. The S5 emphasizes sporty handling more than the Benz, and its all-wheel-drive system offers confident grip in all weather, a benefit in colder climates. These competitors offer similar luxury and performance, but often use a similar amount of gas. For better gas mileage, consider a four-cylinder model, but that reduces the supercharged V6 experience. Looking at S5 MPG across all years highlights the available options.

Tips to maximize efficiency

Pay attention to tire pressure. Properly inflated tires reduce rolling resistance, maximizing fuel economy. Check tire pressures regularly and keep them at the manufacturer’s recommended levels, which are listed on a sticker inside the driver’s side doorjamb.

Anticipate traffic flow. Maintaining a steady speed and avoiding unnecessary acceleration and braking can improve fuel efficiency. Scanning the road ahead allows for smoother driving and reduces fuel consumption.

Avoid extended idling. Modern engines are efficient even from a cold start. Idling for long periods, such as warming up the engine in the winter, wastes fuel. Instead, start driving gently, allowing the engine to warm up.

Use premium fuel as recommended. The Audi S5’s supercharged engine operates best with premium fuel. Using lower-octane fuel can reduce performance and damage the engine. Using the manufacturer’s recommendation ensures efficiency and longevity.