BMW 320d

If you’d told car firms 20 years ago that there was a 161bhp saloon returning 70mpg with emitting 109g/km of CO2, they would have laughed at you. But the 320d EfficientDynamics does all that and more, and without charging a premium. At the other end of the range, the new 335i Coupé and Convertible offer pace to worry an M3, with more style and economy than ever. Once again, BMW has improved performance while boosting fuel economy. The question is, how much further can it go?

The 320d isn’t broken, but BMW is fixing it anyway! A new 2.0-litre diesel engine has been launched, and it also features in the latest EfficientDynamics edition – which is the greenest 3-Series ever.

The changes coincide with the arrival of the facelifted 3 Coupé and Convertible, plus an updated engine in 335i variants.

The new eco-friendly saloon’s turbo common-rail injection unit delivers 380Nm of torque – the same as the standard 320d. And while it offers 20bhp less power, at 161bhp, it’s no slouch, with 0-62mph in eight seconds flat and a 142mph top speed.

More remarkable than that, though, is its combined economy of 68.9mpg and 109g/km CO2 emissions. These figures allow the EfficientDynamics to eclipse its main rival, the Audi A4 TDIe.

Lowered suspension, specially designed 16-inch aerodynamic alloys and Michelin EnergySaver tyres help the BMW slip through the air and tip-toe over the tarmac, saving precious litres of fuel.

The gearing has also been lengthened, while a dual-mass flywheel encourages owners to use as high a ratio as possible by ironing out vibrations at low revs.

On the move, it’s amazing how well BMW has judged the compromise between a sporty driving experience and smooth ride comfort – and how similar the new car feels to the standard 320d. The suspension is firm, but few rivals offer such a great blend of acceptable long-haul comfort with sharp turn-in and beautiful balance when the pace quickens.

The engine feels smoother than the more powerful version fitted to the standard 320d – the latter can sound strained and coarse on full throttle. And with so much torque available, the longer ratios are rarely an issue.

Unlike VW’s BlueMotion range, the EfficientDynamics saloon costs the same as the standard model, despite the considerable benefits it brings. The only turn-off for buyers on paper will be the 20bhp power deficit – as well as the limited scope the car offers for personalisation.

Go for the EfficientDynamics saloon, and you’re forced to stick with the 16-inch alloys, instead of 17-inch wheels as standard. Plus, you can’t specify the M Sport pack – an option that has always been a big hit with UK customers.

Elsewhere in the range, the Coupé and Convertible get a fresh grille, headlights and bumpers. Plus, 335i models are tweaked under the skin. The 3.0-litre straight-six engine has swapped its twin turbos for a single twin-scroll unit. This aims to save weight and boost fuel economy, without sacrificing the lag-free throttle response for which the engine has become famous.

And it works. Power and torque are identical to the outgoing unit, at 302bhp and 400Nm. However, fuel consumption has improved by 2.5mpg to 33.6mpg in the Coupé and 2.7mpg to 32.4mpg in the folding hard-top model.

The heavier Convertible feels marginally slower but sounds superior, while the beautifully weighted steering and lively rear-wheel-drive handling are as impressive as ever in both cars. So both 335is are genuine junior M3s – and when you add this to the impressive 320d EfficientDynamics package, the 3-Series range is better than ever.

Rival: Audi A4 TDIe
The eco A4 can’t match BMW’s cleanest 3-Series for power or efficiency. But it’s still a very impressive package, offering decent economy and emissions without shouting about it.