19 MPG combined from the 2018 BMW 650i xDrive Convertible isn’t going to win over hybrid shoppers or those focusing on saving money at the pump. This number reflects what the car is: a strong, luxurious open-top grand tourer. Buyers seeking the 650i Convertible care about performance, exclusivity, and the thrill of 445 horsepower. Fuel efficiency is less important.

City and highway performance

The EPA estimates the 2018 BMW 650i xDrive Convertible gets 16 MPG in the city and 25 MPG on the highway. This difference shows how the car’s powertrain is calibrated. The 4.4L twin-turbo V8 works best on the open road, where it can cruise at high speeds. However, stop-and-go city driving depends heavily on boost and frequent gearshifts from the eight-speed automatic transmission (S8), which lowers fuel economy. The xDrive all-wheel-drive system improves grip and stability, but it also adds weight and drivetrain losses that cause the lower city MPG rating. This car isn’t made for maximizing efficiency in cities.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2018 BMW 650i xDrive Convertible is $3,050. This is based on driving 15,000 miles per year and using national average fuel prices. Individual fuel costs will vary depending on driving habits, location, and gasoline prices. Fuel is a notable expense, but buyers of this car are unlikely to be concerned, they accept the cost of fueling a high-performance V8. View all Bmw fuel economy data.

Real-world expectations

The EPA’s numbers are a good starting point, but actual fuel economy can change a lot. Driving hard, using Sport mode a lot, and idling for a long time will hurt fuel consumption. On the other hand, driving gently and using the car’s Eco Pro mode (if it has it) during highway driving may improve MPG. Achieving the EPA estimates can be hard because the 650i encourages drivers to put the pedal to the metal. Also, review 650I MPG across all years.

How it compares

The 650i Convertible’s fuel economy is about what you’d expect in the high-performance convertible class. The Mercedes-Benz SL550 with its 4.7L V8 gets around 17 MPG city and 25 MPG highway. A Porsche 911 Carrera S Cabriolet, while known to be efficient, still only gets about 20 MPG city and 27 MPG highway, even with a smaller flat-six engine. The Audi S5 Cabriolet is more fuel-efficient, getting roughly 21 MPG city and 30 MPG highway, but it uses a smaller, less powerful V6 engine is for a different buyer who wants efficiency and all-weather driving more than power. The 650i buyer will trade some MPG for the V8’s sound and the car’s presence.

Tips to maximize efficiency

The 650i xDrive Convertible focuses on performance instead of fuel economy, but owners can still take steps to improve gas mileage. Accelerating gently and watching traffic flow can cut fuel consumption, especially in cities. Avoid flooring it and driving at high speeds for long periods.

Tires that are properly inflated reduce rolling resistance and improve fuel efficiency. Check your tire pressure often and keep it at the level on the door jamb sticker. Low tire pressure increases drag, making the engine work harder and burning more fuel.

Regular maintenance is important for the best fuel economy. Keep the engine tuned and follow the manufacturer’s service schedule. Clean air filters and new engine oil help the engine run well and reduce fuel consumption.

Carry as little weight in the car as possible. Extra cargo increases the vehicle’s load and lowers fuel efficiency. Removing items you don’t need will improve MPG, this is especially true because this vehicle has less trunk space due to the convertible top.

When possible, use cruise control on the highway. Keeping a steady speed saves fuel compared to constant acceleration and deceleration. However, avoid cruise control on hilly roads, as it may cause inefficient gear changes.