The BMW 4 Series Convertible (G23) underwent a Life Cycle Impulse (LCI), or facelift, in March 2024, introducing updates to styling, technology, and powertrain options. The 430i variant, powered by a 2.0-liter turbocharged four-cylinder engine producing 255 horsepower and incorporating mild hybrid technology, represents a key offering within the G23 lineup. Positioned as a mid-range option, it bridges the gap between the base 420i and the higher-performance M440i models, appealing to buyers seeking a balance of performance, luxury, and efficiency in a premium convertible package. This model is primarily targeted towards the North American and European markets, where the demand for premium, open-top vehicles remains strong.
Technical Specifications
| Brand | BMW |
| Model | 4 Series |
| Generation | 4 Series Convertible (G23 LCI, facelift 2024) |
| Type (Engine) | 430i (255 Hp) Mild Hybrid xDrive Steptronic |
| Start of production | March, 2024 |
| Powertrain Architecture | MHEV (Mild Hybrid Electric Vehicle) |
| Body type | Cabriolet |
| Seats | 4 |
| Doors | 2 |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 60 mph | 5.9 sec |
| Maximum speed | 210 km/h (130.49 mph) |
| Weight-to-power ratio | 7.4 kg/Hp, 135.6 Hp/tonne |
| Weight-to-torque ratio | 4.7 kg/Nm, 212.8 Nm/tonne |
| Gross battery capacity | 0.4 kWh |
| Battery voltage | 48 V |
| Battery technology | Lithium-ion (Li-Ion) |
| Battery location | Under the front hood |
| Electric motor power | 11 Hp |
| Electric motor Torque | 25 Nm (18.44 lb.-ft.) |
| Electric motor location | Front, Longitudinal |
| Power | 255 Hp @ 4700-6500 rpm |
| Torque | 400 Nm (295.02 lb.-ft.) @ 1600-4500 rpm |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | B48B20O2 |
| Engine displacement | 1998 cm3 (121.93 cu. in.) |
| Number of cylinders | 4 |
| Engine configuration | Inline |
| Cylinder Bore | 82 mm (3.23 in.) |
| Piston Stroke | 94.6 mm (3.72 in.) |
| Compression ratio | 10.5:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Direct injection |
| Engine aspiration | Twin-power turbo, Intercooler |
| Valvetrain | Double-VANOS, VALVETRONIC |
| Kerb Weight | 1880 kg (4144.69 lbs.) |
| Trunk (boot) space – minimum | 300 l (10.59 cu. ft.) |
| Trunk (boot) space – maximum | 385 l (13.6 cu. ft.) |
| Fuel tank capacity | 59 l (15.59 US gal | 12.98 UK gal) |
| Length | 4773 mm (187.91 in.) |
| Width | 1852 mm (72.91 in.) |
| Width including mirrors | 2081 mm (81.93 in.) |
| Height | 1394 mm (54.88 in.) |
| Wheelbase | 2851 mm (112.24 in.) |
| Front track | 1582 mm (62.28 in.) |
| Rear (Back) track | 1593 mm (62.72 in.) |
| Ride height (ground clearance) | 127 mm (5 in.) |
| Minimum turning circle (turning diameter) | 12 m (39.37 ft.) |
| Number of gears and type of gearbox | 8 gears, automatic transmission Steptronic |
Powertrain & Engine Architecture
At the heart of the 2024 BMW 430i Convertible lies the B48B20O2 2.0-liter inline-four cylinder engine. This engine is a member of BMW’s modular engine family, known for its efficiency and performance. The B48 utilizes a single, twin-scroll turbocharger, direct fuel injection, and BMW’s VALVETRONIC fully variable valve timing and lift control system. The addition of 48V mild hybrid technology enhances efficiency by allowing for features like extended coasting and smoother start-stop operation. The electric motor, integrated into the drivetrain, provides a small power boost during acceleration. The engine is paired with BMW’s eight-speed Steptronic automatic transmission, which offers smooth and responsive shifts. This transmission is programmed for both comfort and performance, adapting to the driver’s style.
Driving Characteristics
The 430i Convertible delivers a refined and engaging driving experience. The 255 horsepower and 295 lb-ft of torque provide ample power for both city driving and highway cruising. Acceleration from 0 to 60 mph takes a claimed 5.9 seconds. While not as overtly sporty as the M440i, the 430i offers a more accessible and comfortable driving experience. The Steptronic transmission is well-tuned, providing seamless gear changes. The mild hybrid system contributes to improved fuel economy and a smoother overall driving feel. Compared to manual transmission versions (no longer offered in the US market for this model), the automatic prioritizes convenience and ease of use. The xDrive all-wheel-drive system provides excellent traction and stability in various weather conditions.
Equipment & Trim Levels
The 2024 430i Convertible comes standard with a comprehensive list of features, including BMW’s iDrive 8 infotainment system with a curved display, leatherette upholstery, power-adjustable front seats, automatic climate control, and a premium sound system. Standard safety features include automatic emergency braking, lane departure warning, and parking sensors. Optional extras include upgraded leather upholstery, a head-up display, a Harman Kardon sound system, and various driver-assistance features like adaptive cruise control and lane keeping assist. The convertible top is a fully automatic soft top, available in several colors, and can be operated at speeds up to 31 mph.
Chassis & Braking
The G23 4 Series 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 of ride comfort and handling precision. The 430i is equipped with ventilated disc brakes on all four wheels, providing ample stopping power. The xDrive all-wheel-drive system distributes power between the front and rear axles as needed, enhancing traction and stability. The steering is an electric power-assisted rack-and-pinion system, offering precise and responsive steering feel.
Market Reception & Comparison
The 2024 BMW 430i Convertible LCI has been generally well-received by automotive critics. Reviewers praise its refined driving experience, comfortable interior, and advanced technology. Compared to the 420i, the 430i offers a noticeable performance upgrade. Against the M440i, it provides a more balanced and affordable option for buyers who prioritize comfort and efficiency over outright performance. Fuel economy is rated at around 25 mpg combined, making it relatively efficient for a premium convertible. Reliability reports are still emerging for the LCI model, but the B48 engine has a generally good reputation for durability.
Legacy
The B48 engine family has become a mainstay in BMW’s lineup, known for its reliability and efficiency. The integration of mild hybrid technology in the 430i Convertible represents BMW’s commitment to improving fuel economy and reducing emissions. The G23 generation 4 Series Convertible, and specifically the 430i variant, is expected to hold its value well in the used car market due to its premium brand image, desirable features, and engaging driving experience. As technology continues to evolve, the 430i will likely be remembered as a transitional model, bridging the gap between traditional internal combustion engines and the future of electrified vehicles.
