The BMW 4 Series Convertible (G23 LCI), specifically the M440i variant introduced in March 2024, represents the facelifted iteration of the G23 generation. This model occupies the performance-oriented segment of the 4 Series Convertible lineup, positioned above the 430i and below any potential future high-performance ‘M’ variants. The LCI (Life Cycle Impulse), BMW’s term for a significant mid-cycle refresh, brings updated styling, enhanced technology, and refinements to the powertrain. The M440i combines a turbocharged inline-six engine with mild-hybrid technology, offering a blend of performance and efficiency in a premium open-top package.
Technical Specifications
| Brand | BMW |
| Model | 4 Series |
| Generation | 4 Series Convertible (G23 LCI, facelift 2024) |
| Type (Engine) | M440i (386 Hp) Mild Hybrid Steptronic |
| Start of production | March, 2024 |
| Powertrain Architecture | MHEV (Mild Hybrid Electric Vehicle) |
| Body type | Cabriolet |
| Seats | 4 |
| Doors | 2 |
| Fuel consumption (urban) | 8.7 l/100 km (27 US mpg) |
| Fuel consumption (extra urban) | 7.1 l/100 km (33.1 US mpg) |
| Fuel consumption (combined) | 8.1 l/100 km (29 US mpg) |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 60 mph | 5 sec |
| Maximum speed | 210 km/h (130.49 mph) |
| Weight-to-power ratio | 5 kg/Hp |
| Weight-to-torque ratio | 3.6 kg/Nm |
| Gross battery capacity | 0.4 kWh |
| Battery voltage | 48 V |
| Battery technology | Lithium-ion (Li-Ion) |
| Electric motor power | 11 Hp |
| Electric motor Torque | 25 Nm (18.44 lb.-ft.) |
| System power | 386 Hp @ 5200-6250 rpm |
| System torque | 540 Nm @ 1900-4800 rpm (398.28 lb.-ft.) |
| Engine Power | 375 Hp |
| Engine displacement | 2998 cm3 (182.95 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | Inline |
| Cylinder Bore | 82 mm (3.23 in.) |
| Piston Stroke | 94.6 mm (3.72 in.) |
| Compression ratio | 11:1 |
| Fuel injection system | Direct injection |
| Engine aspiration | Twin-power turbo, Intercooler |
| Valvetrain | Double-VANOS, VALVETRONIC |
| Kerb Weight | 1924 kg (4241.69 lbs.) |
| Trunk space (min) | 300 l (10.59 cu. ft.) |
| Trunk space (max) | 385 l (13.6 cu. ft.) |
| Fuel tank capacity | 59 l (15.59 US gal) |
| Length | 4773 mm (187.91 in.) |
| Width | 1852 mm (72.91 in.) |
| Height | 1387 mm (54.61 in.) |
| Wheelbase | 2851 mm (112.24 in.) |
| Gearbox | 8-speed automatic (Steptronic) |
Powertrain & Engine Architecture
The heart of the 2024 BMW 4 Series Convertible M440i is the B58B30M2 3.0-liter inline-six engine. This engine is a member of BMW’s modular engine family, known for its smooth power delivery and efficiency. It utilizes direct fuel injection, a twin-scroll turbocharger, and BMW’s VALVETRONIC variable valve timing and lift system, along with Double-VANOS variable camshaft timing. These technologies work in concert to optimize combustion and enhance both performance and fuel economy. The addition of a 48V mild-hybrid system provides an electric boost, assisting the engine during acceleration and enabling smoother start-stop operation. The electric motor, producing 11 horsepower and 25 Nm of torque, is integrated into the drivetrain. Power is transmitted to the rear wheels via an eight-speed Steptronic automatic transmission, known for its quick and precise shifts.
Driving Characteristics
The M440i Convertible delivers a refined yet engaging driving experience. The 386 horsepower and 398 lb-ft of torque provide brisk acceleration, with a 0-60 mph time of around 5 seconds. The mild-hybrid system contributes to a near-instantaneous response from a standstill. The Steptronic transmission is well-tuned, offering smooth gear changes in automatic mode and responsive manual shifts when desired. Compared to the 430i Convertible, the M440i offers a significant performance upgrade. While the 430i prioritizes fuel efficiency and comfort, the M440i leans towards a more sporty character. The gear ratios are optimized for both acceleration and highway cruising, providing ample power in most driving situations. The convertible top mechanism doesn’t significantly impact chassis rigidity, maintaining a composed feel even with the top down.
Equipment & Trim Levels
The M440i Convertible comes standard with a comprehensive list of features, including BMW’s iDrive infotainment system with a large touchscreen display, premium leather upholstery, power-adjustable seats, automatic climate control, and a high-quality sound system. Standard safety features include automatic emergency braking, lane departure warning, and adaptive cruise control. Optional extras include upgraded leather options, a head-up display, a premium sound system from Harman Kardon, and various driver-assistance systems. The LCI update brought revised interior trim options and updated technology features, including enhanced connectivity and over-the-air software update capabilities.
Chassis & Braking
The G23 Convertible utilizes a sophisticated chassis design. The front suspension features a spring-strut setup with a transverse stabilizer, while the rear employs an independent multi-link suspension, also with a stabilizer bar. This configuration provides a good balance between ride comfort and handling precision. The M440i is equipped with ventilated disc brakes on all four wheels, providing ample stopping power. The steering system is an electric power-assisted rack-and-pinion setup, offering precise and responsive steering feel. The standard tire sizes are 225/45 R18 front and 225/45 R18 rear, with optional 19-inch wheels available.
Market Reception & Comparison
The 2024 BMW 4 Series Convertible M440i has been generally well-received by automotive critics. Reviewers praise its powerful engine, refined driving dynamics, and luxurious interior. The mild-hybrid system is noted for its seamless integration and contribution to improved fuel economy. Compared to competitors such as the Audi A5 Cabriolet and Mercedes-Benz C-Class Cabriolet, the M440i is often cited as offering a more engaging driving experience and a more powerful engine. Fuel economy figures of around 29 US mpg combined are competitive within its segment. Reliability reports are still emerging for the LCI model, but the B58 engine has a generally good reputation for durability.
Legacy
The B58 engine is considered one of BMW’s most successful and reliable powerplants. Its robust design and advanced technologies contribute to its longevity. The mild-hybrid integration in the M440i represents a step towards greater electrification in BMW’s lineup. As a used car, the G23 M440i Convertible is expected to hold its value well, appealing to buyers seeking a premium open-top experience with a blend of performance, luxury, and technology. The LCI facelift is likely to further enhance its desirability in the used car market, offering updated styling and features.
