The Alpina B4 Coupe 3.0 (410 Hp) Allrad Switch-Tronic represents a high-performance iteration of the BMW 4 Series Coupe, meticulously engineered by the independent German automotive engineering company, Alpina. Produced between 2014 and 2017, this model occupied a niche position between the standard BMW 4 Series and the more track-focused M4. It aimed to deliver a blend of grand touring comfort, everyday usability, and exhilarating performance, appealing to drivers seeking a refined yet potent coupe experience. The B4 Coupe is based on the BMW F32 4 Series platform, benefitting from Alpina’s signature enhancements to the engine, transmission, suspension, and aesthetics.
Technical Specifications
| Brand | Alpina |
| Model | B4 |
| Generation | B4 Coupe |
| Type (Engine) | 3.0 (410 Hp) Allrad Switch-Tronic |
| Start of production | 2014 |
| End of production | 2017 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Coupe |
| Seats | 4 |
| Doors | 2 |
| Fuel consumption (economy) – urban | 10.6 l/100 km (22.2 US mpg) |
| Fuel consumption (economy) – extra urban | 6.3 l/100 km (37.3 US mpg) |
| Fuel consumption (economy) – combined | 7.9 l/100 km (29.8 US mpg) |
| CO2 emissions | 183 g/km |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 4 sec |
| Acceleration 0 – 62 mph | 4 sec |
| Acceleration 0 – 60 mph | 3.8 sec |
| Maximum speed | 303 km/h (188.28 mph) |
| Emission standard | Euro 6 |
| Weight-to-power ratio | 4.1 kg/Hp |
| Weight-to-torque ratio | 2.8 kg/Nm |
| Power | 410 Hp @ 5500-6250 rpm |
| Power per litre | 137.6 Hp/l |
| Torque | 600 Nm @ 3000-4000 rpm (442.54 lb.-ft.) |
| 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 | 10.2:1 |
| Fuel injection system | Direct injection |
| Engine aspiration | BiTurbo, Intercooler |
| Kerb Weight | 1680 kg (3703.77 lbs.) |
| Max. weight | 2200 kg (4850.17 lbs.) |
| Max load | 520 kg (1146.4 lbs.) |
| Trunk (boot) space – minimum | 445 l (15.72 cu. ft.) |
| Fuel tank capacity | 60 l (15.85 US gal | 13.2 UK gal) |
| Permitted trailer load with brakes (12%) | 1800 kg (3968.32 lbs.) |
| Permitted trailer load without brakes | 750 kg (1653.47 lbs.) |
| Length | 4640 mm (182.68 in.) |
| Width | 1825 mm (71.85 in.) |
| Height | 1373 mm (54.06 in.) |
| Wheelbase | 2810 mm (110.63 in.) |
| Front track | 1551 mm (61.06 in.) |
| Rear (Back) track | 1576 mm (62.05 in.) |
| Drive wheel | All wheel drive (4×4) |
| Number of gears and type of gearbox | 8 gears, automatic transmission Switch-Tronic |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Power steering | Electric Steering |
| Tires size | 245/30 ZR20; 265/30 ZR20 |
| Wheel rims size | 8J x 20; 9J x 20 |
Powertrain & Engine Architecture
At the heart of the B4 Coupe 3.0 lies Alpina’s version of the BMW N55 inline-six engine. While based on the N55, Alpina extensively modified the powerplant, incorporating twin turbochargers, a larger intercooler, and a bespoke engine management system. These enhancements resulted in an output of 410 horsepower at 5500-6250 rpm and a substantial 600 Nm (442.54 lb-ft) of torque available between 3000 and 4000 rpm. The engine utilizes direct fuel injection and a compression ratio of 10.2:1. The exhaust system is also unique to Alpina, contributing to both performance and a distinctive exhaust note.
The transmission is an 8-speed automatic, branded as ‘Switch-Tronic’. This transmission is not simply a re-tuned BMW unit; Alpina recalibrated it for faster shift speeds and more responsive operation. Drivers could also utilize steering wheel-mounted shift paddles for manual control. Crucially, the B4 Coupe featured Alpina’s all-wheel-drive system, providing enhanced traction and stability, particularly in adverse weather conditions. The system is biased towards the rear wheels, offering a more engaging driving experience.
Driving Characteristics
The Alpina B4 Coupe 3.0 delivers a markedly different driving experience compared to the standard 4 Series or even the M4. While the M4 prioritizes outright track performance, the B4 focuses on a more refined and usable power delivery. The twin-turbocharged inline-six provides strong, linear acceleration throughout the rev range, with minimal turbo lag. The Switch-Tronic transmission shifts quickly and smoothly, contributing to a seamless driving experience. The all-wheel-drive system inspires confidence, providing excellent grip in a variety of conditions. The B4 feels less overtly aggressive than the M4, making it a more comfortable and enjoyable grand tourer. The gear ratios are tuned for both acceleration and highway cruising, offering a balance between performance and efficiency.
Equipment & Trim Levels
The B4 Coupe came generously equipped as standard. Interior appointments included Alpina-specific sports seats upholstered in premium leather, an Alpina steering wheel, and unique interior trim elements, such as wood or carbon fiber accents. Standard features also included a navigation system, premium sound system, and a comprehensive suite of safety features. Optional extras included a panoramic sunroof, upgraded leather upholstery, and various driver assistance systems. Alpina offered a degree of customization, allowing customers to personalize their B4 Coupe with a range of exterior and interior options.
Chassis & Braking
Alpina made significant revisions to the chassis to complement the increased power output. The suspension was retuned with stiffer springs and dampers, while also maintaining a comfortable ride quality. The B4 Coupe featured a more robust braking system than the standard 4 Series, with larger ventilated discs at all four corners. ABS (Anti-lock Braking System) was standard. The steering was precise and well-weighted, providing good feedback to the driver. The car’s electronic stability control system was calibrated to allow for a degree of controlled oversteer, enhancing the driving experience.
Market Reception & Comparison
The Alpina B4 Coupe 3.0 was generally well-received by automotive critics. It was praised for its blend of performance, luxury, and refinement. Reviewers noted that it offered a compelling alternative to the BMW M4, particularly for drivers who prioritized comfort and usability over outright track performance. Fuel economy was respectable for a high-performance coupe, averaging around 29.8 US mpg in combined driving. Reliability was generally good, although maintenance costs were higher than those of the standard 4 Series due to the specialized nature of the Alpina components. Compared to the 428i or 435i models, the B4 offered significantly more power and performance, but at a higher price point.
Legacy
The Alpina B4 Coupe 3.0 remains a desirable and relatively rare vehicle in the used car market. The N55 engine, while not without its potential issues (such as oil leaks and cooling system vulnerabilities), is generally considered robust when properly maintained. The Switch-Tronic transmission has proven to be reliable. The B4 Coupe’s unique combination of performance, luxury, and exclusivity has ensured its continued appeal to enthusiasts. Values have remained relatively stable, reflecting the car’s limited production numbers and its status as a collectible Alpina model. Finding a well-maintained example with a complete service history is crucial for prospective buyers.
