The 2012 BMW Alpina B7 is offered in either short- or long-wheelbase versions, as well as rear- or all-wheel drive, all of which are equally well appointed.

Standard features include 21-inch wheels, adaptive xenon headlamps, a power trunk lid, front and rear parking sensors, keyless ignition/entry, a sunroof, a heated steering wheel, a power rear sunshade, rear side sunshades (powered in RWD models), auto-dimming mirrors, four-zone automatic climate control, premium leather upholstery, heated and ventilated power front seats, heated rear seats and wood interior trim. Also standard are a head-up display, a rearview camera, a navigation system with real-time traffic, the BMW iDrive telematics interface, Bluetooth and a 10-speaker audio system with a six-CD changer, digital music storage, satellite radio and iPod and USB input jacks.

The Alpina B7 offers a handful of stand-alone options and packages. The optional Driver Assistance package adds automatic high beams, side and top camera views, and lane departure and blind-spot warning systems, while the Luxury Rear Seating package -- available only on long-wheelbase models -- adds power-adjustable and ventilated seats with massage functions. Stand-alone options include a rear-seat entertainment system, adaptive cruise control, smartphone integration, and night vision with pedestrian detection.

The 2012 BMW Alpina B7 is powered by a twin-turbo 4.4-liter V8 that produces 500 hp and 516 pound-feet of torque. A six-speed automatic is the only transmission available and includes manual shift control via steering-wheel-mounted buttons. In standard form, the B7 comes in a rear-wheel-drive configuration, but all-wheel drive is also available.

In Edmunds testing, a B7 accelerated from zero to 60 mph in an impressively quick 4.5 seconds. The EPA estimates fuel economy at 14 mpg city/22 mpg highway and 17 mpg combined for RWD models, while AWD versions achieve slightly less at 14/20/16 mpg.

Standard safety features on the Alpina B7 include antilock brakes, stability and traction control, front-seat side airbags, front knee airbags and side curtain airbags. Optional safety features include adaptive cruise control with a front collision warning system, a lane-departure warning system, active blind-spot detection, rear- and sideview cameras, and infrared night vision with pedestrian detection that displays the images either in the main dash display or in the head-up display (if so equipped).

In Edmunds brake testing, an Alpina B7 stopped from 60 mph in just 107 feet.

With 500 hp under the hood, the 2012 BMW Alpina B7 is one of the most exhilarating luxury sedans available. All 516 lb-ft of torque is available very early in the power band for acceleration that can pin passengers to their seatbacks. But even with such impressive power, the B7 is remarkably well-mannered when driven conservatively. Gearshifts are fired off quickly and smoothly, with steering-wheel-mounted buttons to allow the driver to manually control the shifting.

The B7 rides lower than the standard 7 Series and features larger 21-inch wheels, yet ride comfort is still pretty much intact. Various dynamic settings that adjust, among other parameters, throttle response and suspension stiffness notably change the car's attitude, as does Alpina's dual-stage traction control; the more conservative Stage One intervenes immediately when it detects wheel slip, while Stage Two gives the driver a longer leash to play with. In the B7's sportiest setting, though, the transmission's shifts are so quick and hard that they become unpleasant.

Subtle differences aside, the 2012 Alpina B7's interior matches the heady mix of executive-class luxury, comfort and cutting-edge technology found in the BMW 7 Series. Supple leather and rich wood accents adorn almost every surface and the available "multicontour" front seats ensure comfort for virtually any body type.

The rear seats similarly accommodate taller adults, and the extended-wheelbase versions offer even more legroom (by about 6 inches) and slightly increased headroom. Available rear seats that can heat, cool and even massage occupants should satisfy even the fussiest riders.

The B7 also adds tasteful Alpina badging and optional wood trims that include ash, myrtle or matte finish (classic Piano Black trim is also available) to distinguish it from the standard BMW 7 Series. Blue backlit gauges and illuminated scuff plates further add to the Alpina's unique character. Like the 7 Series, the Alpina B7 features the BMW iDrive telematics interface, which seems daunting at first but quickly becomes intuitive.