The next-generation BMW 1 Series is coming to town in 2011. New more fuel efficient engines, including a 1.6 turbo and body variants will be available.

New information and speculation regarding the next-generation BMW 1 Series is now available. The car is scheduled to reach dealerships in 2011 and will usher in a wave of changes for the company. If all goes according to plan the 1 Series should become BMW's big volume seller and overtake the 3 Series.

A couple of new body variants will be introduced with the next One, including a four-door sedan aimed at the American market and a kind of GT model. Of course the normal shapes will still apply, that is the coupe and the hatch in five-door, three-door and convertible guises. Our computer generated renderings from our files show a glimpse of what the car could more or less look like when finished.

Because the Z4 has grown in both proportion and price, there may be space for a roadster that falls within the size market of the Mazda MX-5. WCF published a story which quoted a BMW source who said such a roadster was not on the cards because the company already has a car in that market, namely the 1 Series Convertible. Nevertheless this rumour of a roadster is not going anywhere for the moment.

BMW's EfficientDynamics programme is becoming a large part of its philosophy. The 1 Series will also use the programme to benefit customers and the environment. One way of doing this is to downgrade engines and then turbo charge them. So the cars will get a new 1.6-litre turbo whose power is speculated at between 110bhp (82kW) and 160bhp (119kW). The 110bhp engine should be able to return C02 emissions of less than 100g/km and have a range of 70mpg. A 2.0-litre petrol turbo will be added to the menu and will be good for between 150bhp (112kW) and 200bhp (149kW).

Although an M version of the 1er has been denied, a twin turbo 1 Series which is about as close as it will get to an M will be able to achieve over 300bhp (224kW).

Gallery: Next Generation BMW 1 Series: More Details Spill Out