Alpina B3 Biturbo Allrad Touring (E91 2009)

The Alpina B3 (E90) and Alpina D3 (E90) are a series of high performance compact executive cars manufactured by German automobile manufacturer Alpina from 2007 to 2013. Based on the BMW 3 Series (E90), the B3 and D3 were available in coupé, saloon, convertible (not available for the D3) and station wagon body styles. The B3 was officially unveiled at the 2007 Geneva Motor Show.

Development and introduction
Development of the B3 began in 2006. At that time, it was speculated that the car would either be introduced with a 4.4-litre supercharged V8 engine (already used in the B5, B6 and B7) or a naturally aspirated V8 engine (as used in the 550i and 750i). The supercharger would've been Alpina's own design. Both of these speculations were nullified when the car was introduced in 2007 as it utilised a modified version of the BMW N54 inline-6 engine used in the 335i.[5] The B3 was available with rear-wheel-drive or all-wheel-drive drivetrains. The cars equipped with the all-wheel-drive (BMW xDrive) system were called Allrad.

The engine was modified by the addition of an Alpina specific ECU, oil cooler and lighter and stronger MAHLE pistons.[5] These modifications allowed the engine to generate 360 PS (265 kW; 355 hp) between 5,500 rpm to 6,000 rpm and 500 N⋅m (369 lb⋅ft) of torque at 3,800 rpm to 5,000 rpm. The engine has a red-line of 7,000 rpm. The engine was mated to a 6-speed ZF automatic transmission paired with a control system called Switch Tronic. The control system was first introduced by the company in 1993 and has a manual mode which allows the driver to change gears either by the gear lever or by buttons present behind the steering wheel. Shift times had been significantly improved, taking 100 milliseconds to shift gears.

The company re-introduced one of their signature exterior colours for the B3 namely Alpina Green as Alpina Green II.[6] However, the car could be ordered in any colour out of the standard exterior colours as offered on its predecessor. The exterior changes included optional Alpina pinstripes, a front spoiler with Alpina lettering, a rear lip spoiler and a light weight Akrapovic stainless steel exhaust system with quad exhaust tips. The exhaust system had a floating tip design, a first to be used on an Alpina vehicle. Buyers were offered a choice of three 20-spoke alloy wheels: 18 or 19-inch "Classic" (8" and 9" wide) and 19-inch "Dynamic" (set of 5 quadruple spokes, 8.5" and 9.5" wide). Facelift versions had additional "Classic C10" option in 19" (widths remained as in the original ones).

The interior included Alpina logos and lettering, Alpina side sills, heated sport seats, wood trim, Lavalina leather upholstery, cruise control, Alpina floor mats and Alpina gauges with the speedometer reading up to 306 km/h (190 mph) on the European models. The interior could be customised to the customer specifications by the Alpina interior department.

The suspension system of the B3 utilised a mixture of in-house developed components and BMW components. The coupé and cabriolet version used the shocks from the 335i Sport while the Saloon and Wagon variants used the shocks as found on the standard 335i. The coil springs as found on the 335i Sport are used throughout the B3 versions. The rear subframe bushings are the same as those found on the 335d while the secondary springs used are a mixture of those found on the 335xd and 335i Sport. The front stabilisers are the same as used on the 335i Sport while the rear stabilisers are bespoke units which are smaller than those found on the 335i. The use of different stabilisers allow for a better turn in and safe cornering. The suspension geometry is shared with the D3.

The tyres used on the B3 are Michelin Pilot Sport tyres measuring 245/35 ZR19 at the front and 265/35 ZR19 at the rear, different to the sizes of D3 - 235/35 and 265/30, for 19". Later version - D3 Biturbo - used B3 sizes.