For 2014, BMW has dropped a gold standard of its own – the “3” that distinguished its performance two-door coupe since 1978. Though the benchmark-setting four-door 3 Series soldiers on, BMW has carved out a new numerical niche – the 4 Series – for its two-door. The new product nomenclature reserves odd numbers for four-door sedans, and even numbers for two-door coupes.

In short, this means that the ever-popular two-door BMW 3 Series no longer exists. It has been replaced by the car before you. But rather than engaging in a re-badge for re-badging’s sake, BMW has built a better two-door, with the longer, lower, wider stance long championed by performance coupes from US manufacturers, and a new turbocharged four-cylinder engine called on for low-end punch and improved efficiency.

The tested 428i is BMW through and through, from its blue-and-white propeller emblem to its orange-glowing instrument panel. At least until the arrival of the 431hp M4, which made its debut at the2014 Detroit auto show, the six-cylinder 435i is the 4 Series flagship. Like the 428i, the top model can be fitted with a six-speed manual transmission and optional all-wheel-drive. The tested 240hp 2-litre four-cylinder 428i features an eight-speed automatic transmission sending power to just the rear wheels, in the BMW tradition.

That, along with the available variable sport steering, gives the 428i a lively, responsive demeanour down the road, aided in no small part by the lack of a heavy all-wheel-drive system The turbocharged four-cylinder feels stronger than its 240hp rating, with good power from low revs courtesy of the forced induction. Granted, the 428i is no racer, but for the driver who is after a fun daily driver with sleek lines and commendable fuel economy –  the tested car is EPA-certified at 35mpg-on the highway – this is a very sensible choice.

BMW aficionados are enamoured of the brand’s smooth six-cylinder power plants, so the company went to great lengths to civilise the turbocharged four-cylinder unit so that drivers rarely feel they are being punished for their choice.

The engine growls gamely, especially under heavy throttle. The sound is warm and rounded, without the thrashy or coarse character typical of four-cylinders of old. Inside, there is a quiet purr at idle, while outside, the direct fuel injectors deliver a characteristic – and not unpleasant – diesel-like clack that has become the modern sound of efficiency.

Styling for all 4 Series models is unimpeachably sensuous, with the same wheels-to-the-corners stance that gives BMW’s cars some of the best proportions in the industry. While arguably no BMW’s roofline can surpass that of the original 6 Series coupe of 1976 for sheer drama, the 4 Series is a lovely modern interpretation. The rearmost roof pillar, or C-pillar in industry parlance, flows into the trunk with a grace missing from the comparatively hunchbacked Audi A5. That sleekness, however, is achieved at the expense of a useful rear seat. The rear perches are purely decorative, at least where carrying adult passengers is concerned.

BMW’s manual transmission shifters and clutches have long enjoyed anointed status among enthusiasts, so it is nice to see the new eight-speed automatic transmission in the 428i so expertly calibrated, with imperceptible automatic shifts. Drivers should never sense a compromise with either 4 Series gearbox.

Although divine driving dynamics and superb engine response are here, such treasures – like artefacts at Pompeii – lie partially buried under layer after layer of detritus. The wondrous cache of sporting hardware is remarkably well preserved, but the trophy hunter can be stymied trying to access them.

BMW’s iDrive infotainment system  is slightly less confounding here than in other Bimmers, suggesting that the company is headed in the right direction. But the interface still frustrates with layered menus that complicate simple actions and obfuscate the means to make adjustments. The company has adopted other frustrating affectations, such as the need to press the starter button twice to shut the car off; the first press kills the engine and you have to press it a second time to switch off electrical power. Perform the second press with foot on the brake, and the engine may restart.

The automatic transmission shifter is the electronic variety, which is really just a plastic joystick that requests shifts before springing back to center. Push it forward to select Reverse. And don’t forget to squeeze the button on the shifter to ask “pretty please” when requesting a gear or the request will be denied.

BMW’s maladroit execution of the car’s various electronic widgets are a frustrating tarnish on the 428i. But despite a numerological change to its name, the 3 Series’ gold still glitters beneath the new 4 Series badge.