The Alpina B3 Cabrio (E93) 3.0i Biturbo, produced between 2007 and 2012, represents a unique blend of luxury, performance, and open-air driving enjoyment. Based on the BMW E93 3-Series Cabriolet, the B3 was meticulously engineered by Alpina, a renowned German automotive engineering company, to deliver a more potent and refined experience. This variant, equipped with a 3.0-liter biturbo inline-six engine and a Switch-Tronic automatic transmission, occupied the high-performance end of the B3 Cabriolet range, offering a significant step up from the standard 3-Series models and even the naturally aspirated B3 variants.
Technical Specifications
| Brand | Alpina |
| Model | B3 |
| Generation | B3 Cabrio (E93) |
| Type (Engine) | 3.0i Biturbo (360 Hp) Swtch-Tronic |
| Start of production | 2007 |
| End of production | 2012 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Cabriolet |
| Seats | 4 |
| Doors | 2 |
| Fuel consumption (urban) | 14 l/100 km (16.8 US mpg, 20.2 UK mpg, 7.1 km/l) |
| Fuel consumption (extra urban) | 7.2 l/100 km (32.7 US mpg, 39.2 UK mpg, 13.9 km/l) |
| Fuel consumption (combined) | 9.7 l/100 km (24.2 US mpg, 29.1 UK mpg, 10.3 km/l) |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 5 sec |
| Acceleration 0 – 62 mph | 5 sec |
| Acceleration 0 – 60 mph | 4.8 sec |
| Maximum speed | 280 km/h (173.98 mph) |
| Emission standard | Euro 5 |
| Weight-to-power ratio | 5.1 kg/Hp, 195.1 Hp/tonne |
| Weight-to-torque ratio | 3.7 kg/Nm, 271 Nm/tonne |
| Power | 360 Hp @ 5500-6000 rpm |
| Power per litre | 120.8 Hp/l |
| Torque | 500 Nm @ 3800-5000 rpm (368.78 lb.-ft. @ 3800-5000 rpm) |
| Engine layout | Front, Longitudinal |
| Engine displacement | 2979 cm3 (181.79 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | Inline |
| Cylinder Bore | 84 mm (3.31 in.) |
| Piston Stroke | 89.6 mm (3.53 in.) |
| Compression ratio | 9.4:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Multi-port manifold injection |
| Engine aspiration | Turbocharger, Intercooler |
| Valvetrain | DOHC |
| Kerb Weight | 1845 kg (4067.53 lbs.) |
| Max. weight | 2200 kg (4850.17 lbs.) |
| Max load | 355 kg (782.64 lbs.) |
| Trunk (boot) space – maximum | 430 l (15.19 cu. ft.) |
| Fuel tank capacity | 63 l (16.64 US gal | 13.86 UK gal) |
| Length | 4580 mm (180.31 in.) |
| Width | 1782 mm (70.16 in.) |
| Height | 1395 mm (54.92 in.) |
| Wheelbase | 2760 mm (108.66 in.) |
| Front track | 1503 mm (59.17 in.) |
| Rear (Back) track | 1512 mm (59.53 in.) |
| Drivetrain Architecture | The Internal combustion engine (ICE) drives the rear wheels of the vehicle. |
| Drive wheel | Rear wheel drive |
| Number of gears and type of gearbox | 6 gears, automatic transmission |
| Front suspension | Spring Strut |
| Rear suspension | Coil spring |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Tires size | 245/40 R18ZR; 265/40 R18ZR |
INTRODUCTION
The Alpina B3 Cabrio (E93) 3.0i Biturbo was produced from 2007 to 2012, representing a high-performance variant of the BMW E93 3-Series Cabriolet. Alpina, independent of BMW but working in close collaboration, enhanced the 3-Series with significant engine upgrades, suspension tuning, and interior refinements. The B3 Cabriolet aimed to provide a more exclusive and dynamically engaging driving experience than the standard 3-Series, appealing to customers seeking a blend of luxury, performance, and open-top motoring. It sat at the top of the B3 Cabriolet range, offering the most powerful engine option available.
Powertrain & Engine Architecture
At the heart of the B3 Cabrio 3.0i Biturbo lies Alpina’s modified version of BMW’s N54 inline-six engine. This 3.0-liter engine utilizes twin turbochargers, intercooling, and a sophisticated engine management system to produce 360 horsepower and 500 Nm (368 lb-ft) of torque. The engine code is closely related to the BMW N54, but with Alpina-specific calibrations and components. Fuel is delivered via multi-port fuel injection, and the engine features a double overhead camshaft (DOHC) valvetrain. The turbochargers are not the standard BMW units; Alpina employed lower-inertia turbochargers for improved throttle response.
The “Switch-Tronic” transmission is a ZF 6HP21 automatic gearbox, heavily modified by Alpina. It features a unique shift program optimized for performance and smoothness. Drivers could also manually select gears via steering wheel-mounted paddles, providing a degree of control typically associated with manual transmissions. The transmission is designed to handle the increased torque output of the biturbo engine and deliver seamless gear changes.
Driving Characteristics
The B3 Cabrio 3.0i Biturbo delivers exhilarating performance. The twin-turbocharged engine provides strong acceleration throughout the rev range, with minimal turbo lag. The 0-60 mph sprint takes approximately 4.8 seconds, and the car boasts a top speed of 280 km/h (174 mph). The Switch-Tronic transmission contributes to a smooth and refined driving experience, while the manual shift mode allows for more spirited driving. Compared to the naturally aspirated B3 variants, the 3.0i Biturbo offers a substantial increase in power and torque, resulting in noticeably quicker acceleration and improved passing performance. The automatic transmission, while offering convenience, doesn’t quite match the engagement of a manual gearbox, but the Switch-Tronic system mitigates this with its responsive shift speed and manual control options.
Equipment & Trim Levels
The Alpina B3 Cabrio 3.0i Biturbo was generously equipped as standard. Interior features included premium leather upholstery, Alpina-specific interior trim (often featuring wood or carbon fiber accents), sport seats, and a high-end audio system. Standard exterior features included Alpina’s signature aerodynamic body kit, including a front spoiler, rear diffuser, and subtle trunk lid spoiler. Alpina’s multi-spoke alloy wheels were also standard. Optional extras included a premium sound system upgrade, navigation system, heated seats, and a variety of exterior color options. The interior ambiance was focused on luxury and sportiness, differentiating it from the standard BMW 3-Series Cabriolet.
Chassis & Braking
Alpina made significant revisions to the chassis and suspension to complement the increased power output. The suspension was retuned with stiffer springs and dampers, and the ride height was lowered slightly. This resulted in improved handling and reduced body roll. The B3 Cabrio 3.0i Biturbo featured ventilated disc brakes on all four wheels, providing ample stopping power. ABS (Anti-lock Braking System) was standard. While the suspension was firmer than the standard 3-Series, Alpina managed to maintain a reasonable level of ride comfort, making the B3 Cabriolet suitable for both spirited driving and long-distance cruising.
Market Reception & Comparison
The Alpina B3 Cabrio 3.0i Biturbo was well-received by automotive critics, who praised its performance, refinement, and exclusivity. It was often compared favorably to the BMW 335i Cabriolet, with reviewers noting the Alpina’s superior engine tuning and more luxurious interior. Fuel economy was reasonable for a high-performance convertible, averaging around 24.2 US mpg in combined driving. Reliability was generally good, although the twin-turbocharged engine required more diligent maintenance than the naturally aspirated variants. The B3 offered a unique proposition – a high-performance convertible that wasn’t as overtly aggressive as some of its competitors, such as the Porsche 911 Cabriolet.
Legacy
The Alpina B3 Cabrio (E93) 3.0i Biturbo remains a desirable used car today. The N54 engine, while known for some potential maintenance issues (such as fuel injector and turbocharger failures), is generally robust when properly maintained. The Switch-Tronic transmission is also considered reliable. The B3 Cabriolet’s combination of performance, luxury, and exclusivity has ensured its continued appeal to enthusiasts. Values have remained relatively stable, reflecting the car’s rarity and the enduring reputation of the Alpina brand. It represents a compelling alternative to the standard BMW 3-Series Cabriolet for those seeking a more special and engaging driving experience.
