27 MPG combined isn’t going to win any awards, but it’s perfectly acceptable for the 2016 BMW 428i Convertible. This isn’t a car bought for hypermiling; it’s purchased for open-air thrills, a certain image, and the promise of BMW’s renowned driving dynamics. Fuel efficiency is a consideration, to be sure, but rarely the main reason for buying.

City and highway performance

The EPA estimates suggest 23 MPG in the city and 34 MPG on the highway. The city figure reflects the stop-and-go nature of urban driving, where the 428i’s turbocharged engine works harder and its automatic transmission cycles through gears more frequently. The highway number, however, is genuinely respectable.

With the top down and the wind in your hair on an open road, the 2.0L engine settles into a relaxed cruise, using fuel relatively sparingly. The eight-speed automatic transmission (S8) plays an important role here, keeping the engine in its optimal efficiency range. Commuters who spend a significant portion of their time on the highway will find the 428i Convertible a surprisingly pleasant companion, balancing enjoyment with reasonable fuel consumption.

Annual fuel cost

The EPA calculates the annual fuel cost for the 2016 BMW 428i Convertible at $2,150. This figure is based on driving 15,000 miles per year, assuming a national average fuel price. Individual fuel costs will vary depending on driving habits, local fuel prices, and the grade of gasoline used (premium is recommended).

While this number might seem high compared to a hybrid or a compact car, it’s important to remember the context. We are talking about a luxury convertible offering a specific blend of performance and desirability. The annual fuel cost is a trade-off many buyers are willing to make for the experience the 428i provides.

Real-world expectations

While the EPA provides a standardized benchmark, real-world fuel economy invariably differs. Aggressive driving, frequent short trips, and heavy traffic can all negatively impact MPG. Conversely, careful acceleration, consistent speeds, and long highway journeys can improve fuel economy.

Owners reporting their own figures on sites like Fuelly suggest that achieving the EPA’s 27 MPG combined is realistic for many drivers, but exceeding it consistently requires a conscious effort to drive efficiently. Remember to check 428I MPG across all years to get a better picture.

How it compares

The 428i Convertible exists in a niche segment, but comparisons are still relevant. The Audi A3 Cabriolet, for example, offers a similar blend of luxury and open-top driving. The A3 Cabriolet’s 1.8T engine achieves around 29 MPG combined, slightly better than the 428i. However, the Mercedes-Benz C300 Convertible, with its 2.0L turbo engine, is closer with its 25 MPG combined.

Buyers often cross-shop these models, weighing factors like styling, features, and brand prestige alongside fuel efficiency. If fuel economy is a top priority, the A3 offers a slight advantage. If you are curious, take a look at all Bmw fuel economy data.

Tips to maximize efficiency

Take it easy on the throttle. The 428i’s turbocharged engine delivers plenty of power, but aggressive acceleration burns fuel unnecessarily. Smooth, gradual acceleration, especially from a standstill, will significantly improve your MPG. Allow the engine to build boost progressively rather than demanding it instantly.

Use the Eco Pro mode. This driving mode changes the throttle response, shift points, and climate control settings to prioritize fuel efficiency. While it might slightly dull the car’s responsiveness, it’s a worthwhile option for daily commuting or long highway stretches where maximum performance isn’t required.

Maintain proper tire inflation. Underinflated tires increase rolling resistance, forcing the engine to work harder and consume more fuel. Check your tire pressures regularly and inflate them to the recommended levels outlined on the driver’s side doorjamb. A simple adjustment can make a noticeable difference.

Minimize idling. Letting the engine idle for extended periods wastes fuel. If you’re stopped for more than a minute or two, it’s generally more efficient to turn off the engine. Modern starters are designed for frequent use, so restarting the engine won’t cause undue wear and tear.