BMW 320d

This BMW is clearly aimed at the fleet market, but there are some fantastic benefits for private buyers, too. Fuel economy is up by 10mpg over a standard 320d, while CO2 emissions of 109g/km mean road tax bills of only £35 a year. Despite the energy-saving changes, the talented rear-drive chassis and torquey engine mean it’s still a polished driver’s car. The EfficientDynamics can’t be specified with the M Sport pack, but buyers who want a 320d will find there’s no real sacrifice in going for the green option.

It’s the greenest 3-Series ever produced, and it doesn’t mind shouting about it! The all-new 320d EfficientDynamics is the first car to include the eco-branding in its name. It emits only 109g/km of CO2 – yet has 50 per cent more power and torque than any other model in its emissions sector.

Sitting next to the regular 320d in the range, it offers drivers a real eco option, while retaining the class-leading dynamics that make the 3-Series such a hit. Under the bonnet is the same 2.0-litre turbocharged diesel engine, detuned by 14bhp to 161bhp, but with 10Nm more torque at 360Nm.

The addition of a dual-mass flywheel – already fitted to BMW’s six-cylinder diesels – reduces vibration and noise at low speeds. This encourages you to change up earlier and run the engine more efficiently. As with all four-cylinder 3-Series since 2007, it gets stop-start, brake regeneration and electric power-steering as standard.

On top of this, though, the new car features lowered suspension, longer gear ratios and reduced engine friction. A new wheel design improves aerodynamics, while Michelin EnergySaver tyres minimise rolling resistance. The result is the best economy and emissions of any model in the BMW stable, with the exception of the MINI Cooper D.

Yet if you throw eco driving out of the window, there’s still real pace on offer. It covers 0-62mph in 8.2 seconds – only a second slower than a VW Golf GTI.

Amazingly, the changes don’t affect driving fun. Road noise is minimal, despite the eco tyres, and the suspension is supple. Plus, the engine is smooth and punchy – this car is just as taut and agile as the existing 320d.

But the best part is the price: it costs the same as a standard 320d SE and has identical kit. So, buyers can choose between a car designed for performance or low emissions without having to consider costs or spec.

Rival: Insignia ecoFLEX
Vauxhall’s green family car nearly matches the BMW for pace, although it trails in terms of fuel economy. However, it weighs in at £2,000 less – so if badge appeal isn’t important to you, it’s a tempting option.