"A four-cylinder in the 2012 BMW 5 Series? Have they lost their minds?" We can hear this refrain echoing across the country as people read that BMW has replaced the iconic inline-6 engine in its midsize luxury sedan with a measly four-banger. The current 5 Series has already received criticism among the BMW faithful for sacrificing its sporting charm in favor of comfort and size. While we're still apt to agree with that sentiment, any concerns about the new four-cylinder are unfounded. In fact, it's a welcome development.

The new four-cylinder found in the entry-level 528i is direct-injected and features BMW's innovative twin-scroll turbocharger that prevents lag and maximizes performance across the rev range. The result is 240 horsepower, the same as last year's normally aspirated 3.0-liter inline-6, as well as 255 pound-feet of torque, a substantial boost of 30 lb-ft. The result is actually quicker acceleration, and thanks to its smaller displacement and the new automatic stop/start feature (also standard on the carryover 535i), the 528i achieves a truly impressive estimated 23 mpg city/34 mpg highway and 27 mpg combined. Only the Audi A6 2.0T bests that, but it has a less powerful four-cylinder.

Besides the 528i's new motivation, the rest of the 5 Series range continues on for 2012 -- albeit with a recalibrated throttle that rids the car of last year's irritating lag when you pressed the accelerator. There are still buttery-smooth engines in the 535i and 550i, while a wealth of available equipment remains waiting to make your driving life easier (and push the price to stratospheric levels). Last year's complete redesign plumped out the car's dimensions and sense of isolation; in many ways, the latest 5 is a less sporting car than it once was. But on the other hand, it's also more spacious and comfortable.

In total, the 2012 BMW 5 Series is a top choice among midsize luxury sedans, but we can no longer say it's the easy choice it once was. The Audi A6, Infiniti M, Jaguar XF and Mercedes-Benz E-Class are all stronger than the 5 in key areas and deserve close consideration. If there's one thing that shouldn't be held against the 5 Series, however, it's the new four-cylinder engine. It may seem weird, but times are changing and such downsizing is going to become the norm.

The 2012 BMW 5 Series is a midsize luxury sedan available in three trim levels that correspond with engine choice: 528i, 535i and 550i. The high-performance M5 model is reviewed separately.

Standard equipment on the 528i includes 17-inch wheels, adjustable driving settings (alters suspension, steering, throttle and automatic transmission response), automatic and adaptive bi-xenon headlights, LED running lights, foglights, automatic wipers, heated mirrors, a sunroof, cruise control and auto-dimming mirrors. Inside you get dual-zone automatic climate control, eight-way power front seats with four-way power lumbar and driver memory functions, leatherette premium vinyl upholstery and a power tilt-and-telescoping leather-wrapped steering wheel. Electronic features include the BMW Assist emergency communications system, Bluetooth, the iDrive electronics interface and a 10-speaker sound system with a CD player, HD radio, an auxiliary audio jack and an iPod/USB audio interface.

The 535i gets a six-cylinder engine, 18-inch wheels and leather upholstery. The 550i gets a V8 engine, front and rear parking sensors, a rearview camera, 14-way multicontour power front seats and a navigation system with real-time traffic and a larger iDrive screen. All of these extra luxury and convenience features are available on the respective lower trim levels.

There is a wealth of other options available on every 5 Series trim, many of which are available within packages or as individual options. These include keyless ignition/entry, a power trunk lid, active cruise control, an automatic parallel parking system, Integral Active Steering, a blind-spot warning system, a lane-departure warning system, automatic high beams, headlight washers, side/top-view parking cameras, a head-up display and an infrared night-vision display. Inside you can add on four-zone automatic climate control, heated front and rear seats, ventilated front seats, a heated steering wheel, a sport steering wheel, a split-folding rear seat, a power rear sunshade, manual rear side sunshades, a rear seat entertainment system, satellite radio and a premium sound system.

The Sport package adds bigger wheels, adaptive suspension dampers, a sport steering wheel, an increased top speed and the multicontour seats. The M Sport package adds to those items a special aerodynamic body kit, special wheels and an M Sport steering wheel.

The 2012 BMW 528i is powered by a 2.0-liter turbocharged four-cylinder that produces 240 hp and 255 lb-ft of torque. As with every 5 Series, rear-wheel drive is standard and "xDrive" all-wheel drive is optional. Also standard is an eight-speed automatic transmission and an automatic stop/start function that shuts down the engine when the car stops in order to save fuel. In Edmunds performance testing, a 528i went from zero to 60 mph in 6.4 seconds -- more than a half-second quicker than the old six-cylinder 528i. BMW-estimated fuel economy is 23 mpg city/34 mpg highway and 27 mpg combined with rear-wheel drive and 22/32/26 with all-wheel drive.

The 2012 BMW 535i gets a 3.0-liter turbocharged six-cylinder that produces 300 hp and 300 lb-ft of torque. Rear-wheel-drive models get a standard six-speed manual or an optional eight-speed automatic; all-wheel-drive models are automatic only. Automatic stop/start is standard. In Edmunds performance testing, a rear-drive 535i with the automatic went from zero to 60 mph in 5.9 seconds. BMW-estimated fuel economy is 19/29/23 with the manual, 21/31/25 with rear-wheel drive and the automatic and 21/30/24 with all-wheel drive.

The 2012 BMW 550i gets a turbocharged 4.4-liter V8 that produces 400 hp and 450 lb-ft of torque. The same transmission and drive options from the 535i are available on the 550i, with the exception of auto stop/start. In Edmunds performance testing, a rear-drive automatic-equipped 550i went from zero to 60 in 5.2 seconds. EPA-estimated fuel economy is 15/23/18 with the automatic and rear-wheel drive, 15/22/17 with the manual and rear-wheel drive and 16/24/18 with all-wheel drive.

Standard safety equipment for the 2012 BMW 5 Series includes stability and traction control, antilock disc brakes, front-seat side airbags, side curtain airbags, active front head restraints and the BMW Assist emergency communications system. The stability control system integrates several features designed to improve braking performance, such as periodically wiping the brake rotors dry in wet conditions and automatically snugging the brake pads to the rotors when the driver abruptly lifts off the throttle.

When equipped with active cruise control, the 5 Series also comes with a pre-collision system that can warn the driver of the possibility of rear-ending a vehicle ahead. If a collision is imminent, it can also automatically apply the brakes. A lane-departure warning system and a blind-spot monitor are optional. The night-vision system is capable of displaying possible hazards that are otherwise out of regular headlight range.

In Edmunds brake testing, various 5 Series models with the Sport package's summer tires came to a stop from 60 mph in distances ranging from 110 to 114 feet. Those are excellent numbers, but typical for summer tires.

In government crash tests, the 5 Series earned a top five-star rating for overall performance, with four out of five stars being given for overall front-impact protection and five stars for overall side-impact protection. In Insurance Institute for Highway Safety testing, the 5 Series earned a top rating of "Good" in the frontal-offset, side-impact and roof-strength crash tests.

It wasn't too long ago that the high-performance M5 was throwing down 400 hp. Now you get that (plus a lot more torque) out of the latest 550i, which accelerates as quickly as a V8 sport coupe but without the pretentious bombast. Choosing the 300-hp 535i or even the less potent 528i is hardly like sitting in the cheap seats; most people will be more than satisfied with their power. Putting a four-cylinder engine in a large sedan like the 5 Series may seem like a bad idea, but you'd be hard-pressed to tell the 528i has only four cylinders firing underhood. In fact, it gives up only a half-second to the 535i when accelerating from zero to 60.

Regardless of which engine you choose, the 2012 BMW 5 Series comes standard with BMW's Driving Dynamics Control, which alters the suspension, steering, throttle and automatic transmission response based on four driver-selected settings. This is a nice idea in theory, as it allows drivers to set up the car as they'd like, but in reality, only Sport mode comes close to achieving the sort of control feel the 5 Series used to possess. Unfortunately, the car also always defaults back to Comfort mode when you turn off the car, regardless of which mode was selected previously.

Handling has always been a hallmark of the BMW 5 Series, and although it's still a strong suit, the current model lacks the agility and communication of its predecessors. The steering transmits less feel, the larger dimensions make it feel bulky on tighter roads and there's just a general feel of isolation that didn't exist before. Our editors and BMW customers alike have lamented this change; however, the 5 Series' quieter cabin, more comfortable ride and lighter steering in parking lots may appeal more to the masses than before.

Both drivers and passengers will be quite pleased with the 5 Series' cabin. There's nothing particularly fancy going on, but the overall look of the dash is clean thanks to the standard iDrive interface that eliminates the need for a gaggle of buttons. The layout features a center display screen and a configurable display in the gauge cluster. The iDrive controller, thanks to its physical buttons and menu structure, is pretty easy to figure out and provides a large amount of customization of the car's features. Opting for the navigation system is recommended, as its screen is larger and much better-looking than the standard center display.

The front seats are quite comfortable, with the optional multicontour seats in particular providing an unmatched degree of adjustability. In back, there's enough room for a pair of 6-foot adults to be comfortable, and the backseat is nicely contoured and padded. The trunk, at 14 cubic feet of luggage capacity, is smaller than average for this segment.