Sector: Compact Executive Price: €30,200–€53,860 Fuel: 3.8–7.9l/100km CO2: 99–185g/km

While BMW might seem focused on niche models, the 3 Series is a reminder that its core products are the most important. Claimed to be the figurehead of its driver-focused brand identity, the sedan and Touring account for a quarter of BMW’s global sales, with 14 million sold in the 40 years since the line was first introduced.

But the car that was once the pioneer now faces competition not only from other German brands, but from a resurgent Lexus, Jaguar and soon Alfa Romeo too. With this mid-cycle refresh, the 3 Series is reasserting itself against rivals’ latest innovations – three-cylinder engines, a plug-in hybrid and sub-100g/km CO2 emissions among them.

Visually, it’s an easy update to miss, comprising LED-lined headlights similar to the Concept 4 Series Coupe from 2013, and a few accents of chrome inside. Mercedes-Benz still has the segment lead on cabin aesthetics, but it’s hard to pick fault with the fuss-free solidity of Munich’s efforts. A high-speed LTE data connection means the navigation system can download map updates for free for the first three years, which is good news for business users.

Drivetrains are the focus this time, particularly the petrol engines which are now based on a 500cc-per-cylinder modular design. For the first time, the 3 Series range kicks off with a 1.5-litre, three-cylinder turbocharged petrol engine, topped out by the effortlessly fast 340i straight-six, which delivers effortless, linear acceleration with surprisingly low CO2 emissions from 168g/km. There’s no three-cylinder diesel yet, but it can only be a matter of time.

Absent from the new range is the ActiveHybrid 3, a model never that well-tuned to European tastes, but its shoes are more than filled by the 330e plug-in hybrid due next year. With a combined 252hp from the combination of petrol and electric power, and 35km of electric range available at high speed, this will offer tax-conscious CO2 emissions of 49g/km and official fuel consumption figures of 2.0l/100km. BMW reckons it should have plenty of corporate appeal.

But it’s the staple 320d versions which are likely to continue to be the corporate favourites. This badge covers two versions – the upgraded 190hp model consumes as little as 4.0l/100km, while emitting 106g/km, and the lower, more streamlined 320d EfficientDynamics Edition takes the 3 Series sedan under 100g/km for the first time. The latter does take a drop in power to 163hp, though, and the 3.8l/100km economy figure is only achieved with the eight-speed automatic gearbox.

Regardless of engine choice, the 3 Series still sets a high standard for driver enjoyment in this segment. Stiffer pickup points, revised dampers based on the M235i and a re-tuned steering setup lightly polish what was already a fine driver’s car, balanced, agile and communicative. But, as with the styling, it’s hardly a black-versus-white transformation.

In reality, it didn’t need to be. There’s been a clear evolution of BMW’s sports-sedan lineage through six generations of the car, and in a market full of niches, the 3 Series is a deservedly popular slice of enjoyable familiarity. 

Verdict:

Minor mid-life revisions and double-digit CO2 emissions show BMW hasn’t got to change much for the 3 Series to hold its own in this segment.