The BMW 1 Series has been on sale for just over two years in Britain, with more than 51,000 sales accounting for a significant chunk of the 200,000 sold worldwide. This week, BMW revealed details of the rumoured three-door model, as well as a sizeable number of upgrades across the range that focus on efficiency and reducing the cost of ownership.

BMW's designers have given the 1 Series a mild facelift to accompany the new engines; essentially new bumpers, a larger grille and changes to the lights. The new three-door shares this new look and retains the roofline of the five-door. However, the doors are longer and are frameless, giving the three-door a sportier feel. Appropriately, buyers of the three-door can choose between a four and five-seat layout, and in an attempt to maintain a sportier image some of the entry-level engines are not available on the three-door model.

New technology headlines the six engine line-up (118d, 120d, 116i, 118i, 120i and 130i). Brake Energy Regeneration is new and uses Intelligent Alternator Control and a special battery to recover energy during braking, as well as only using the engine to provide energy to the alternator when required. BMW claims that this alone offers a 3% improvement in fuel economy. Next up is the adoption of Automatic Start-Stop across the range on manual models (130i excepted), which turns off the engine when the car is at a stop. The driver can disable the system at any time. On top of this, the use of electric power steering uses 90% less energy than a conventional hydraulic system, as it only saps engine power when the wheel is being turned. Finally, the airflow to the engine is controlled via flaps mounted behind the grille, which close to improve aerodynamic efficiency when possible.

The use of these new bits helps to reduce fuel consumption (and hence CO₂ emissions), but there have been improvements to the engines too, including the adoption of direct injection on the 120i and 118i. Essentially, BMW claims to have reduced fuel consumption and emissions across the range, while at the same time upping power output and performance.

Keep an eye on the BMW Road Tests page for our impressions on the revamped 1 Series range later this year, following the car's debut at the Geneva Motor Show in March.

Shane O' Donoghue - 18 Jan 2007