The Blue Roundel's compact coupe delivers big grins.

As the replacement for the 3-Series Coupe, BMW's 4-Series has the unenviable task of improving upon one of the best-rounded sport/luxury rides of the last decade.

With sharp, sinewy lines and classic proportions, it certainly looks the part. But it'll need to be much more than just a pretty face to meet the heightened expectations with which it's saddled.

Can the 4-Series one-up its storied predecessor in more than name? Ride along as we find out.

What is it?

The 4-Series follows BMW's latest naming convention, in which even-numbered monikers refer to two- and four-door-coupes, and odd numbers denote sedans. It also follows the industry trend of new model growth, being one inch longer and nearly two inches wider than the 3-Series Coupe. On the plus side, height has decreased by half an inch, giving the two-door the lowest center of gravity of any Blue Roundel ride save the exotic i8 hybrid sports car.

Our test model was the 435i, which is powered by BMW's proven turbocharged 3.0-liter inline six-cylinder with 300 horsepower and 300 lb-ft of torque. Configured in front engine, rear drive fashion, it was equipped with an eight-speed automatic transmission, although purist (read: not poseur) drivers can select a six-speed manual transmission instead, at no additional cost.

While the 435i is the top of the 4-Series lineup until the M4 arrives in spring, more frugal buyers can also opt for the 428i and a turbocharged 2.0-liter four-cylinder rated at 240-horsepower and 255 lb-ft of torque. BMW's xDrive all-wheel-drive system is a further option.

As with its predecessor, the 4-Series is based on the architecture of the 3-Series sedan. Fine-tuned for this application, the kit uses aluminum bits extensively in front in the form of torque struts and wishbones. The rear is made up of a five-link independent rear suspension that has been refined further than that found in the old 3-Series Coupe. Speed-sensitive power steering is standard with BMW's Servotronic system for precise steering input and feedback. Ours, on the other hand, was equipped with the available Dynamic Handling Package and its variable sport steering activation, for livelier turn-in and handling (depending on the driver's input) while leaving a corner.

Our tester was also ordered with an M-Sport package, which included the brand's adaptive M Suspension with automatically adjusting sport dampers. With the center console-mounted Driving Experience Control switch, the adaptive kit allowed us to go from ECO Pro mode to Comfort, Sport or Sport+ settings depending on our mood at the moment. Also included as part of package were sport seats, an aero kit and 18-inch alloy performance wheels, and other M division go-fast goodies. Rounding up, or as in this case, slowing down the package, was the M-Sport brake kit.

It's worth noting that even before options are tacked on, the 4-Series is about $4,000 dearer than the 3-Series Coupe.

What's it up against?

The 435i faces off against such rivals as the Audi A5, the Mercedes-Benz C-Class Coupe, and the Infiniti Q60 (formerly G37). Joining the fray in the not-too-distant future is the Cadillac ATS Coupe.

Look carefully, because many of these models can be configured in ways to satisfy the most specific of buyers. For those who like their driving done al-fresco style, a new convertible will be along in quarter one of 2014.

How does it look?

At first glance, it doesn't appear as though much has changed in the process of the 3-Series Coupe morphing into the 4-Series. After further examination, however, viewers will notice a certain hunkering down that is taking place, almost including the appearance of a chop-top roofline. The latest face of BMW is evident with the headlamps blending into the edges of the twin-kidney grille openings.

Other new cues include wide flares over the wheels and a character line that runs from the front fender rearward.

To go along with the sleeker styling, BMW has implemented new aero measures in the form of air curtains in the front fascia and air breathers - more commonly known as fender vents - located behind the wheel openings. Trimming airflow around the front clip, the setup minimizes turbulence from the front wheel set.

And on the inside?

Well-executed, the interior of our 435i displayed the functionality and playfulness of a Hugo Boss suit. A sculpted binnacle nicely revealed the analog gauges in the driver's IP, while a 6.5-inch display mounted above the centerstack allowed visual control of the 4's iDrive system. Our tester was equipped with the standard, but fine-sounding AM/FM/CD/HD radio audio system. We have still yet to figure out the attraction of HD Radio, but whatever. Curiously, this car was lacking a navigation system, which is available at additional cost as part of the Technology Package.

Our cut-rate 435i (as if $54,425 could be classified as cut-rate) coupe featured a two-tone black and beige leather interior. With the nice contrast of color inside this hot rod, it offered a welcome respite from the sometimes dark, cave-like appearance of all-black cockpits. The M-Sport front seats offered good holding ability with no fatigue for long-haul cross-country tours. In back, there are surprisingly comfortable accommodations with adequate legroom, although we personally would not like to spend more than an hour or two there.

A series of diamond-patterned aluminum trim pieces offered a pleasant counterpoint to the dominating black dash area. We found soft touch material in almost every place with which driver and passengers will come into contact. The gauge system is riding the fence between economy and performance readouts. Rather schizophrenic in nature, it seems the 435i can't decide whether it wants to be known as a fuel miser or a performance vehicle.

But does it go?

New model, same "Ultimate Driving Machine." Power from the straight-six engine was either instantaneous and thunderous or smooth and docile, depending on our mood. The eight-speed gearbox was precise and sure without the hunting found in other examples. BMW says 0-60 mph with the eight-speed clicks off in an even 5.0 seconds. With the manual transmission, it takes three tenths of a second longer.

The EPA says that this 3,610-pound corner-carver achieves 22 city/32 highway with a combined 25 mpg. We weren't far off, achieving a 24.6 mpg average in combined driving.

With the Driving Experience Control system set to Sport mode, the 435i's personality turned playful, with increased steering effort and quicker throttle response for when some throwdown was needed. Not surprisingly, we found EcoPro to be the anti-sport mode, offering a rather intrusivestart / stop function, which finds the engine roughly refiring the split second your foot is lifted from the brakes. We appreciate the car's frugality, but welcome the day this type of system becomes seamless or more "in the background" than its current iteration.

While the DEC's Normal setting is plenty firm for most drivers, we thoroughly enjoyed the 435i's go-kart like handling as displayed in Sport+ mode. Winding through the turns with its electrically-boosted steering reaffirmed to us how the brand continues to grab the enthusiast driver by the throat.

And we like it.

Leftlane's bottom line:

Its pricing isn't for the faint of heart, but the 435i's MSRP buys a worthy successor to the 3-Series Coupe.

Stylish, well-furnished and fleet, the 435i delivers nearly all that could be expected of a sporty luxury two-door.

2014 BMW 435i Coupe base price, $46,000. As tested, $54,425.

M-Sport package, $3,100; Dynamic Handling Package, $1,000; Premium Package, $2,200; M-Sport brakes, $650; Destination, $925.

Photos by Mark Elias.