The BMW 8 Series Convertible (G14) 840i Steptronic, produced from 2020 to March 2022, represents a modern interpretation of BMW’s luxury grand touring heritage. Positioned as a mid-range offering within the G14 8 Series Convertible lineup, it slots between the base 840i models and the high-performance M8 variants. The G14 generation marked BMW’s return to the 8 Series nameplate after a nearly two-decade hiatus, aiming to recapture the spirit of the original E31 8 Series while incorporating contemporary technology and design. This variant specifically caters to drivers seeking a blend of performance, luxury, and open-air driving enjoyment with the convenience of an automatic transmission.
Technical Specifications
| Brand | BMW |
| Model | 8 Series |
| Generation | 8 Series Convertible (G14) |
| Type (Engine) | 840i (333 Hp) Steptronic |
| Start of production | 2020 |
| End of production | March, 2022 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Cabriolet |
| Seats | 4 |
| Doors | 2 |
| Fuel consumption (urban) | 9.5-9.7 l/100 km (24.8 – 24.2 US mpg, 29.7 – 29.1 UK mpg, 10.5 – 10.3 km/l) |
| Fuel consumption (extra urban) | 5.9-6.2 l/100 km (39.9 – 37.9 US mpg, 47.9 – 45.6 UK mpg, 16.9 – 16.1 km/l) |
| Fuel consumption (combined) | 7.2-7.5 l/100 km (32.7 – 31.4 US mpg, 39.2 – 37.7 UK mpg, 13.9 – 13.3 km/l) |
| CO2 emissions | 166-172 g/km |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 5.5 sec |
| Acceleration 0 – 62 mph | 5.5 sec |
| Acceleration 0 – 60 mph | 5.2 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Emission standard | Euro 6d |
| Weight-to-power ratio | 5.5 kg/Hp, 181 Hp/tonne |
| Weight-to-torque ratio | 3.7 kg/Nm, 271.7 Nm/tonne |
| Power | 333 Hp @ 5500-6250 rpm |
| Power per litre | 111.1 Hp/l |
| Torque | 500 Nm @ 1700-4000 rpm (368.78 lb.-ft. @ 1700-4000 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | B58B30C |
| 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 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Direct injection |
| Engine aspiration | Twin-power turbo, Intercooler |
| Valvetrain | VALVETRONIC |
| Engine oil capacity | 6.5 l (6.87 US qt | 5.72 UK qt) |
| Kerb Weight | 1840 kg (4056.51 lbs.) |
| Max. weight | 2340 kg (5158.82 lbs.) |
| Max load | 500 kg (1102.31 lbs.) |
| Trunk (boot) space – minimum | 350 l (12.36 cu. ft.) |
| Fuel tank capacity | 68 l (17.96 US gal | 14.96 UK gal) |
| Length | 4843 mm (190.67 in.) |
| Width | 1902 mm (74.88 in.) |
| Height | 1339 mm (52.72 in.) |
| Wheelbase | 2822 mm (111.1 in.) |
| Front track | 1627 mm (64.06 in.) |
| Rear (Back) track | 1642 mm (64.65 in.) |
| Ride height (ground clearance) | 118 mm (4.65 in.) |
| Drag coefficient (Cd) | 0.29 |
| Minimum turning circle (turning diameter) | 11.6 m (38.06 ft.) |
| Drivetrain Architecture | Rear wheel drive |
| Number of gears and type of gearbox | 8 gears, automatic transmission Steptronic |
| Front suspension | Double wishbone |
| Rear suspension | Independent multi-link suspension |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
INTRODUCTION
The BMW 840i Convertible Steptronic, launched in 2020, is a luxury four-seater convertible built on the G14 platform, which is a derivative of the G12 8 Series Coupe. It represents BMW’s attempt to re-enter the large luxury convertible market, competing with vehicles like the Mercedes-Benz S-Class Cabriolet and the Porsche 911 Cabriolet. The 840i variant, equipped with the B58 engine and Steptronic automatic transmission, was designed to offer a balance between performance and comfort, appealing to buyers who prioritize a refined driving experience over outright track capability. It was produced until March 2022, when BMW made adjustments to its model lineup.
Powertrain & Engine Architecture
At the heart of the 840i Convertible lies the BMW B58B30C 3.0-liter inline-six engine. This engine is a member of BMW’s modular engine family and is renowned for its smooth power delivery and efficiency. The B58 utilizes direct fuel injection, a twin-scroll turbocharger, and BMW’s VALVETRONIC variable valve timing and lift system. VALVETRONIC allows for precise control of valve timing and lift, optimizing engine performance and fuel economy across a wide range of driving conditions. The engine produces 333 horsepower at 5500-6250 rpm and 500 Nm (368.78 lb-ft) of torque between 1700 and 4000 rpm.
The engine is paired with BMW’s 8-speed Steptronic automatic transmission. This transmission features a torque converter and offers smooth, quick shifts. It includes features like Launch Control and shift paddles for manual gear selection, allowing drivers to tailor the driving experience to their preferences. The transmission is longitudinally mounted, driving the rear wheels, a configuration consistent with BMW’s traditional focus on rear-wheel-drive dynamics.
Driving Characteristics
The 840i Convertible Steptronic delivers a refined and engaging driving experience. While not as aggressively tuned as the M8, the 840i offers ample power for comfortable cruising and spirited driving. The 3.0-liter engine provides strong acceleration, with a 0-60 mph time of around 5.2 seconds. The Steptronic transmission contributes to smooth and seamless gear changes, enhancing the overall driving experience. The rear-wheel-drive configuration provides a balanced feel, and the car exhibits predictable handling characteristics. Compared to a manual transmission equipped 840i, the Steptronic version prioritizes ease of use and comfort over outright driver involvement. The automatic transmission’s programming is geared towards smooth transitions and fuel efficiency, making it ideal for long-distance journeys.
Equipment & Trim Levels
The 840i Convertible came standard with a comprehensive list of luxury features. Interior appointments included leather upholstery, power-adjustable seats with memory function, a premium sound system, and a large infotainment display with iDrive controller. Standard safety features included automatic emergency braking, lane departure warning, and adaptive cruise control. Optional extras included upgraded leather options, a head-up display, a Bowers & Wilkins Diamond Surround Sound System, and various driver-assistance systems. The convertible top was a fully automatic soft top, available in several colors, and could be raised or lowered in around 15 seconds at speeds up to 30 mph.
Chassis & Braking
The 840i Convertible features a sophisticated chassis designed to provide both comfort and handling. The front suspension utilizes a double-wishbone design, while the rear suspension employs an independent multi-link setup. This configuration helps to minimize body roll and provide a smooth ride. The car is equipped with ventilated disc brakes on all four wheels, providing ample stopping power. The braking system is assisted by ABS (Anti-lock Braking System) and electronic brake-force distribution. The steering system is an electric power steering system, offering precise and responsive steering feel.
Market Reception & Comparison
The 840i Convertible was generally well-received by automotive critics. Reviewers praised its luxurious interior, refined driving experience, and powerful engine. However, some critics noted that the car’s weight and size could make it feel less agile than smaller sports cars. Compared to the 840i Coupe, the Convertible offered a similar driving experience but with the added enjoyment of open-air motoring. Fuel economy was considered reasonable for a vehicle of its size and performance, with combined fuel consumption figures ranging from 7.2 to 7.5 l/100 km. Reliability reports have been generally positive, with the B58 engine proving to be a robust and dependable unit.
Legacy
The BMW 840i Convertible (G14) represents a significant step forward in BMW’s luxury convertible offerings. The B58 engine has established itself as a highly regarded powerplant, known for its performance and reliability. On the used car market, the 840i Convertible holds its value well, attracting buyers who appreciate its combination of luxury, performance, and open-air driving experience. While the G14 generation was relatively short-lived, it has cemented the 8 Series’ return as a flagship grand tourer in BMW’s lineup, and the 840i variant remains a desirable choice for discerning drivers.
