What's this all about?

It's time the BMW 3 Series came in for a mid-life update, to keep it fresh in the face of the arrival of an all-new Audi A4 and, of course, the impressive new Jaguar XE. Coincidentally, the 3 Series has turned 40 as well.

Have you used images of the old car by mistake?

Cutting. These are the correct pictures and no, there isn't much to say about the changes to the exterior or interior of the car. The lights front and rear have been redesigned (and there's a high-tech all-LED option with Selective Beam for the headlamps for the first time), there are changes to the front bumper, new exhaust outlets, plus fresh wheel and colour options. Inside, slightly revised storage and the addition of gloss-black and chrome detailing seem to be the changes of note, though all examples of the 3 Series now come with satellite navigation as standard, which is claimed to help strengthen the car's residual values even further.

So what is new?

Mostly the engines. BMW has fitted its new 1.5-litre three-cylinder petrol powerplant to the 318i for starters and updated the 2.0-litre turbocharged four-cylinder petrol models too. The 328i has been renamed the 330i and has more power than before at 252hp. Performance stats are 0-62mph in 5.9 seconds (5.8 when fitted with the optional automatic transmission) and 155mph all-out. Above that, there's an all-new turbocharged six-cylinder petrol engine under the bonnet of the 340i model, putting out 326hp and 450Nm of torque. It does 0-62mph in 5.2 seconds (or 5.1 with an auto) and should have no trouble hitting its 155mph limiter.

What about the diesels?

There's even more choice in the diesel line-up and all engines have been updated. In terms of the entry-level 2.0-litre four-cylinder diesels - the 316d, 318d and 320d - increases in performance seems to go hand in hand with improvements in economy and emissions across the board. Highlight figures include emissions of 109g/km from the 316d Saloon, while the updated 320d engine produces 190hp and 400Nm of torque for 0-62mph in as low as 7.2 seconds and emissions of 111g/km.

The new 320d EfficientDynamics Plus is sure to be a huge seller. It's available in Saloon and Touring estate body styles and comes with a headline emissions figure of 99g/km with fuel economy of 74.3mpg. Power comes from a 163hp/400Nm version of the 320d's 2.0-litre engine and with a 0-62mph time of as low as 7.8 seconds, it's still quicker than the 'dirtier' 318d.

Performance diesel fans aren't neglected in the updates. The rear-drive 330d (it can be specified with xDrive all-wheel drive optionally) has a considerable 258hp and 560Nm of torque at its disposal, enabling it to sprint to 62mph in 5.6 seconds, while officially returning 56.5mpg and emitting 131g/km. However, the revised 335d really stands out as being a bit special. Its twin-turbocharged six-cylinder diesel engine now produces 313hp and 630Nm of torque (that'd be why BMW fits xDrive as standard...), which means 0-62mph in 4.8 seconds. It still manages an official 51.4mpg and 145g/km of CO₂.

Any other changes under the skin?

Nothing major, though BMW has said that it has firmed up the suspension a tad, in a bid to better control body movements. Along with that there have been changes to the two gearboxes. The six-speed manual's flywheel is a dual-mass item and features centrifugal pendulum absorbers that allow smoother low-speed running. There's also 'engagement speed control', which automatically blips the throttle on gear downchanges to smoothen them out. Meanwhile, the excellent eight-speed automatic has been revised in a bid for better efficiency and BMW reckons the modifications, including a coasting mode, add up to a three per cent reduction in CO₂ emissions.

Actually, you've not mentioned a hybrid model...

That's because it doesn't arrive in the UK until 2016. It's called the BMW 330e and it's a plug-in hybrid vehicle, so owners can charge its battery pack up at home. The electric-only range is 22 miles using an 80kW electric motor and BMW quotes combined economy of 134.5mpg and an emissions rating of 49g/km. Aiding that motor is the 184hp version of BMW's turbocharged 2.0-litre four-cylinder petrol engine. Maximum system outputs are quoted as 252hp and 420Nm with 0-62mph in 6.3 seconds. All of those figures are provisional incidentally.