Alpina BMW D4 Bi-Turbo Convertible
The BMW ALPINA D4 Bi-Turbo Coupé and Convertible take the lead in the segment of sporty and luxurious two-door models powered by diesel engines. The sublime combination of power, torque, efficiency and smooth handling make for a flawless driving experience. The 3.0 litre straight-six diesel engine with Bi-Turbo charging harmonises seamlessly with the 8-Speed Sport-Automatic Transmission and grant the sporty Coupé and the elegant Convertible with thrilling performance.
The first D3 to come out of Buchloe appeared in 2005 as a turbocharged, 2.0 litre in-line four cylinder model, and delivered a number of surprises - it was not the first diesel to wear the ALPINA badge, but it was unusual for ALPINA not to lead the performance table and instead go with an engine that albeit extremely economical had a small displacement. This D3 later advanced to become the Bi-Turbo, acquiring significantly more driving culture and performance in the process. Together with an extensive range of body styles and the typical harmonious interaction of performance, poise and handling, this model became the highest selling BMW ALPINA to date, with a total of over 2000 vehicles delivered.
Since 2013 the extremely successful and proven straight-six 3.0 litre diesel engine with Bi-Turbo charging, well known from the D5 Bi-Turbo and the XD3 Bi-Turbo, is also available in the multi-award winning BMW 3-Series. With over thirteen hundred deliveries to date (incl. D3 Bi-Turbo), the combination of effortless performance and excellent fuel economy in a compact body has proven to be very popular - in fact these models have become a press favourite when pitched against much larger capacity, thirsty petrol equivalents.
The design of the BMW ALPINA D4 Bi-Turbo Coupé combines muscular and delicate elements in one chic silhouette. The Coupé is longer, wider and significantly lower than the Saloon.Its profile rakes from an imposing, muscular front accentuated with bold lines to a clean and stylish rear. The front spoiler, with subtle ALPINA lettering, integrates seamlessly into the dynamic front apron which is characterised by large air intakes for the cooling system of the turbo-charged engine, the transmission and the high-performance fixed-calliper brake system. Together with the rear spoiler the Coupé's aerodynamics are optimised for excellent high-speed stability while simultaneously maintaining a low drag coefficient. It is almost as if the low, elongated silhouette of the Coupé was shaped to complement the ALPINA CLASSIC wheels. Their timeless, twenty spoke design with hidden air valves suit it exceptionally well. Blue brake callipers with ALPINA lettering and signature twin tailpipes complete the sporty appearance.
The introduction of a diesel powered BMW ALPINA convertible is a significant novelty in the ALPINA company history spanning almost 50 years. BMW ALPINA convertibles based on the BMW 3 respectively 4-Series have for many decades been enjoyed by a small and particularly loyal group of enthusiastic owners. The BMW ALPINA D4 Bi-Turbo Convertible continues this success, and fills a very specific niche. It offers abundant, effortless power and long-distance cruising ability in an elegant and stylish silhouette - regardless of whether the roof is up or down. The refinement, harmonious power delivery and high power reserves of the straight-six 3.0 litre diesel engine with Bi-Turbo charging make it perfectly suited as a means of propulsion for the versatile BMW 4-Series convertible with its metal folding-roof.
The design is characterized by short overhangs, precise, long-drawn-shoulder lines, a wide rear and the characteristic metal folding roof. The sporty and purposeful-front spoiler features functional air intakes and operates in conjunction with the modest rear spoiler to improve stability at high speeds. When the roof is open the BMW ALPINA D4 Bi-Turbo Convertible stands out with its sleek, clean look. The ALPINA CLASSIC 19" light alloy wheels lend it a particularly elegant presence. It only takes 20 seconds and the press of a button to close the roof, which is possible up to a speed of 18 km/h, turning the Convertible into a winter- and weather-proof two-door. The shape of the roof line when closed differs from the BMW ALPINA D4 Bi-Turbo Coupé significantly due to the steeper rake of the rear windscreen, the flat boot lid and subtle rear spoiler - giving it a very distinctive and stand-alone appearance.
The Bi-Turbo drivetrain draws on the excellent characteristics of the underlying BMW fully aluminium, straight-six 3.0 litre capacity engine, the latest generation of common rail direct injection and a two-stage turbocharger with variable turbine geometry. With the freedom that a small series provides, the ALPINA engineers have further exploited the potential of this drive unit and in particular reduced pressure losses by optimising the intake paths and achieved effective de-throttling of the intake paths from the air intake to the air filter body, which results in more power and a more responsive engine. By also exploiting the achievable charge air and injection pressure, this gives a maximum power output of 257 kW (350 hp) at 4000 rpm and an impressive 700 Nm of torque between 1500 and 3000 rpm.
The output of the entire cooling management system has a decisive influence on the stability and performance of charged engines - so cooling of central importance in the BMW ALPINA D4 Bi-Turbo. A large-volume intercooler with optimised inlets and outlets supplies the engine with fresh air. Two radiators positioned in front of the wheel arches for ideal airflow ensure optimal operating temperatures for all coolants - even under peak thermodynamic loads. An exhaust manifold made from the super-strong material D5S allows the maximum exhaust temperature associated with the high power output to be increased by 50 C. The treatment of exhaust gases with a maintenance-free diesel particulate filter and an NSC catalytic converter (NOx storage catalytic converter) facilitates compliance with the EU6 emission standards.
With its sensitive sound application and reduced silencer volume, the exhaust system provides a surprisingly throaty soundtrack for a diesel, especially at higher engine speeds. Beyond the centre silencer, it has a special pipe layout in stainless steel, which ends in two elliptical twin tailpipes bearing the ALPINA and Akrapovi logos. It is a real delight to extract the revving characteristics of the engine in a way that is somewhat untypical for a diesel and to enjoy the performance and torque in the compact 4-Series bodywork.
In addition to the considerable specific output of 86 kW (117 hp) per litre of capacity, the excellent combined fuel consumption of the Coupé impresses at just 5.3l/100km and 139g/km of CO2, respectively 5.9l/100km and 155g/km of CO2 for the Convertible.
The hardware of the 8-Speed Sports-Automatic Transmission with ALPINA SWITCH-TRONIC, developed in collaboration with ZF, is explicitly aimed at satisfying the requirements of the high torque generated by the BMW ALPINA D4 Bi-Turbo. The adapted mechatronics and a special torque converter ensure that power is transmitted with maximum efficiency and comfort to the drive wheels on the rear axle. With regard to the software, the ALPINA engineers have given the transmission extraordinarily pronounced comfort and sports characteristics. High torque at low engine speeds combined with 8 speeds offers very fast gear changes in Automatic Mode - effortless and low-consumption cruising in high gears becomes a pleasure. In addition to Automatic Mode, the transmission has two further transmission modes re-worked by ALPINA. Sport Mode is lively, more dynamic - the gears are held for longer and the shift times are shorter. In Manual Mode, the driver takes over full control of each gear change and uses the SWITCH-TRONIC buttons on the back of the steering wheel to personally select the gear, depending on the traffic and roadconditions. Despite the constantly high torque curve, the system can also perform multiple downshifts in fractions of a second.
The ECO PRO mode activates much more defensive transmission and accelerator pedal characteristics, which in conjunction with other BMW Efficient Dynamicsmeasures, such as the automatic start-stop function and sailing, make a considerable contribution to reducingfuel consumption, depending on personal driving behaviour.
Like every automobile made by ALPINA the D4 Bi-Turbo places special demands on its chassis. The intelligent chassis layout permits a high level of comfort over long distances and in urban traffic, as well as marked driving dynamics and sportiness. The adaptive ALPINA sports chassis solves this conflict of interests by means of electronically adjustable dampers in collaboration with stiffer springs, additional springs and anti-roll bars. It allows the driver to use the Drive Experience Control to select the chassis setting and dynamic properties (Eco Pro, Comfort, Sport, Sport+). Subtle measures taken on the elastokinematics as well as on the camber and toe-in values adapted to the wheel/tyre combination achieve the neutral handling that is typical of ALPINA. The 19" ALPINA CLASSIC wheels with MICHELIN Pilot Sport 4 S tyres, in conjunction with a stiffening of the body at the front of the car, contribute to the high level of accuracy, precise steering behaviour and light handling. The Drive Experience Control also controls further parameters that influence the driving dynamics, such as the power steering and the driving stability control system. The latter is subject to an ALPINA-specific coding.The variable sports steering from BMW, which is installed as standard, has a progressive characteristic that significantly reduces the steering movements required when parking, for example. Optimal braking values are provided by a high-performance brake system, with 370 mm discs at the front and 345 mm discs at the rear. Aluminium callipers (4-piston on front axle, 2-piston on rear axle) painted in blue and bearing the ALPINA logo, in conjunction with highly temperature-resistant pads, ensure high fading stability.
New ALPINA CLASSIC 20" forged wheels with revised, minimalistic design. A reduction in unsprung mass results in even sharper handling and precise steering and also leads to enhanced comfort.
In order to ensure brisk and dynamic driving also in the winter months, an 19" ALPINA CLASSIC winter wheel set is available with Continental ContiWinterContact TS 830P M+S tyres all round (8 x 19" at front, 9 x 19" at rear) with 245/35 R19 93W XL M+S.
Both the Coupé and the Convertible sit on 19" ALPINA CLASSIC wheels, the ALPINA aerodynamic components fit nicely into the modern design without intruding. The functional design of the front spoiler ensures the effective flow of air to various cooler modules and the brake air ducts. In combination with the rear spoiler, this achieves excellent downforce, which contribute significantly to driving stability, in particular at high speeds. The BMW ALPINA D4 Bi-Turbo models have an extensive range of standard equipment, including sports seats, air conditioning with two-zone control and LED-headlights. The interior is dominated by refined materials and a wonderful ambiance. The door sills, floor mats, emblems in the seatbacks, the blue instrument cluster and a hand-stitched sports steering wheel in the finest LAVALINA leather make discreet references to the car's exclusive origins.
Virtually no limits are placed on the individual design of a BMW ALPINA. From the paintwork to the interior trims to the colour of the upholstery - everything offered by the extensive BMW and ALPINA equipment range is available. Seldom does a BMW ALPINA leave the plant in Buchloe without making use of the virtually limitless personalisation options offered by the ALPINA factory. Our philosophy dictates that the customer can design his or her interior individually - assembled by skilled craftsmen in our leather workshop.
