BMW · 2015
650i Convertible 4.4L 8-cyl
✓ EPA Verified
Premium Gasoline
Subcompact Cars
Rear-Wheel Drive
City
17
MPG
Combined
20
MPG
Highway
24
MPG
Annual Fuel Cost
$2,900
Based on 15,000 miles/year · EPA estimates
vs avg gas vehicle
$750
more per year
Class Comparison — Subcompact Cars
Bottom 21%
Better than 21 out of 100 vehicles in its class for fuel efficiency.
This vehicle: 20 MPG
This vehicle
20 MPG
Class average
27 MPG
Class lowest
12 MPG
EPA Energy & Environment Scores
5
Energy Score
Out of 10
5
GHG Score
Out of 10
441 lbs
Annual CO₂
g/mile tailpipe CO₂
Yes
Start-Stop
Auto stop-start
Vehicle Specifications
Engine4.4L 8-cyl
TransmissionAutomatic (S8)
DriveRear-Wheel Drive
Fuel TypePremium Gasoline
Vehicle ClassSubcompact Cars
Engine DescSIDI
Start-StopYes
EPA Vehicle ID34903

Owners of the 2015 BMW 650i Convertible likely glance at its 20 MPG combined fuel economy rating and quickly forget about it. This isn’t a car bought for sensible commutes or lower fuel costs. It’s a statement, a reward, and a visceral experience delivered by a potent V8 engine, and fuel efficiency isn’t usually a priority for the typical 650i Convertible driver. They favor the drop-top experience, the snarling exhaust, and the effortless power over squeezing every last mile from a gallon of premium fuel.

City and highway performance

The EPA estimates for the 2015 BMW 650i Convertible are 17 MPG in the city and 24 MPG on the highway. The lower city figure reflects the nature of stop-and-go driving. The 4.4L V8, producing 445 horsepower, needs more fuel to get its weight moving from a standstill or through slow-speed traffic. The highway figure is more respectable, but still unimpressive compared to smaller-engined rivals. On the open road, the 650i’s smooth eight-speed automatic transmission helps maintain a steady and relatively efficient cruise. However, accelerating too quickly will diminish any chances of achieving that 24 MPG rating.

Annual fuel cost

The EPA calculates the annual fuel cost for the 2015 BMW 650i Convertible at $2,900. This figure is based on driving 15,000 miles per year and using national average fuel prices. This is just an estimate, and your actual fuel costs will depend on your driving habits, the type of driving you do (city versus highway), and local fuel prices. Drivers who frequently accelerate to enjoy the V8’s power or drive primarily in congested urban areas can expect to spend considerably more than this figure. Checking all Bmw fuel economy data before deciding on a purchase is worth considering.

Real-world expectations

The EPA provides a benchmark, but real-world fuel economy often differs. Many 650i Convertible owners report that achieving the EPA’s 20 MPG combined figure is optimistic, particularly if they spend a lot of time in city traffic or enjoy spirited driving. Expect figures closer to 15-18 MPG in mixed driving conditions. On long highway trips, it is possible to reach or slightly exceed the 24 MPG rating, but only with conscious effort and gentle acceleration.

How it compares

Compared to other sporty luxury convertibles of its time, the 2015 BMW 650i Convertible’s fuel economy is at the lower end. For example, the Audi S5 Cabriolet (with its supercharged V6) achieves a combined EPA rating of 21 MPG, a noticeable improvement. Even the Jaguar F-Type Convertible with its supercharged V6 manages around 23 MPG combined. The Porsche 911 Carrera Cabriolet, a more direct competitor, gets around 22 MPG combined. These differences might seem small, but they can add up over time and are worth considering based on driving habits. Also see 650I MPG across all years to help with your decision. However, the 650i Convertible’s target buyer is usually less concerned about these savings and more focused on power, luxury, and the presence of a large V8 engine.

Tips to maximize efficiency

Fuel economy might not be the primary concern for 650i Convertible drivers, but there are ways to reduce fuel consumption. Avoid aggressive acceleration and hard braking. The 650i’s strong engine responds instantly to throttle inputs, but gentle acceleration saves fuel.

Ensure that tires are properly inflated. Underinflated tires increase rolling resistance, forcing the engine to work harder. Regularly check tire pressures and maintain the recommended levels specified in the owner’s manual.

Reduce unnecessary weight. Carrying extra cargo in the trunk adds to the vehicle’s overall weight, reducing fuel efficiency. Remove items you don’t need to lessen the load on the engine.

Use cruise control on the highway. Maintaining a consistent speed reduces acceleration and deceleration, improving fuel economy during long drives. Be mindful of traffic conditions and disengage cruise control when needed.

Think about using a lighter grade of gasoline than Premium fuel (91 octane). BMW recommends premium. The engine will likely run fine on a lower grade, but test it and see if you like the performance. Check if you notice a drop in fuel mileage before switching full time.