BMW has concentrated on improving the efficiency of the 3 Series and there are benefits right across the board. The three-cylinder petrol engine records CO2 emissions of just 122g/km (with the eight-speed Steptronic transmission), a 12% improvement over the previous BMW 316i. Fuel consumption is equally impressive, with the saloon returning up to 54.3mpg and the Touring estate version 51.4mpg. The 320i isn't far behind with CO2 emissions of 134g/km and fuel consumption of 48.7mpg.
Of course, most UK customers will look to the diesel engines and they're not going to be disappointed. For example, the 316d returns up to 68.9mpg, with CO2 emissions of only 109g/km. Go for the pokier 320d and though you get more power (up from 184 to 190PS), emissions have been reduced by 6% to just 111g/km, not at all bad for a car that can hit 143mph.
The Steptronic automatic transmission option now features a coasting mode so that when the driver lifts off the throttle at higher speeds, for example on a gentle downhill grade on the motorway, the engine is automatically decoupled from the powertrain. It then simply ticks over in neutral, which saves fuel and ensures there is no unwanted engine braking at high speed. An additional fuel-saving feature, which also improves driving comfort, is the new Proactive Driving Assistant, which uses information from the navigation system to ""anticipate"" upcoming roundabouts, corners and junctions and select exactly the right time to change gear.