23 MPG combined is a compromise most 2020 BMW 840i xDrive Convertible owners readily accept. They aren’t prioritizing ultimate fuel efficiency; they crave open-air motoring, the assertive power of a turbocharged inline-six, and the surefootedness of all-wheel drive , a potent blend of performance and luxury that places fuel costs a distant second. This isn’t a vehicle chosen for hypermiling; it’s chosen for weekend getaways and making an entrance.

City and highway performance

The EPA estimates the 840i xDrive Convertible achieves 20 MPG in the city and 27 MPG on the highway. The city rating is realistic for stop-and-go traffic where the engine’s stop/start system tries to deliver incremental savings. However, the turbocharged engine’s eagerness to respond to throttle inputs can hinder achieving the stated number. The 27 MPG highway rating is achievable on longer cruises, especially when using cruise control. This figure reflects the engine’s effortless cruising ability and the smooth-shifting 8-speed automatic transmission’s ability to select the optimal gear for efficiency at higher speeds. For those considering other BMW models, all all Bmw fuel economy data is available.

Annual fuel cost

The EPA calculates the annual fuel cost for the 2020 BMW 840i xDrive Convertible at $2,500. This figure is based on driving 15,000 miles per year and using national average fuel prices. It is an estimate, of course, and individual fuel costs will vary based on driving habits, local fuel prices, and the prevailing weather conditions. Owners who frequently engage the engine’s full potential can expect to exceed this annual fuel cost. The figure provides a good baseline for comparison against other vehicles in this class, but remember that premium fuel is required for optimal performance and long engine life from this BMW engine, potentially driving up costs further.

Real-world expectations

While the EPA ratings offer a benchmark, real-world fuel economy often varies. Expect slightly lower figures in mixed driving scenarios, especially if regular short trips are the norm. Aggressive driving, heavy acceleration, and frequent use of the Sport driving mode will all negatively impact fuel consumption. Conversely, drivers who prioritize gentle acceleration, anticipate traffic flow, and use the Eco Pro mode can potentially achieve figures closer to, or even slightly exceeding, the EPA estimates. Keep in mind that wind resistance, especially with the top down, is a significant factor. Also know that the 20″ alloy wheels can also have a negative effect on your fuel economy due to their added weight.

How it compares

Compared to its rivals, the 840i xDrive Convertible’s fuel economy is roughly on par. The Mercedes-Benz SL 450, with its 3.0L V6, achieves a combined 22 MPG. The Porsche 911 Carrera Cabriolet, known for its performance, fares similarly achieving 20 MPG city, 27 MPG highway, and 23 MPG combined with its base engine but this is with the rear wheel drive model. The Audi S5 Cabriolet, with its turbocharged V6 and quattro all-wheel drive, is rated at 20 MPG city, 29 MPG highway, achieving 23 MPG combined. These figures demonstrate that fuel economy isn’t a significant differentiator in this segment. Buyers are more likely to be swayed by factors such as styling, performance, and brand cachet than by a few MPG difference. For more details, check out the 840I MPG across all years.

Tips to maximize efficiency

Gentle acceleration is key to maximizing fuel efficiency in the 840i xDrive Convertible. Avoid aggressive starts and hard braking, as these actions consume more fuel. Allow the engine to warm up gradually before demanding full power. Remember that the turbocharged engine is sensitive to throttle inputs, so a smooth and steady driving style will yield the best results.

Use the car’s driving modes effectively. Select Eco Pro mode for everyday commuting and highway cruising. This mode adjusts the engine mapping, transmission shift points, and climate control settings to prioritize fuel efficiency. Sport mode, while offering enhanced performance, consumes significantly more fuel; reserve it for occasional spirited driving.

Proper tire inflation is critical for optimal fuel economy. Check your tire pressures regularly and maintain them at the recommended levels. Underinflated tires create more rolling resistance, which reduces fuel efficiency. Refer to the sticker on the driver’s side doorjamb for the correct tire pressure specifications.

Minimize unnecessary weight in the vehicle. Remove any cargo that isn’t essential, as added weight increases fuel consumption. A lighter car requires less energy to accelerate and maintain speed. Even small amounts of extra weight can have a cumulative effect on overall fuel economy.

Plan your routes to avoid excessive stop-and-go traffic whenever possible. Idling consumes fuel without covering any distance. Opt for routes that offer more consistent speeds and fewer traffic lights. Using navigation apps that provide real-time traffic updates can help you avoid congested areas and improve fuel efficiency.