Despite the fact that the current generation BMW 3 Series has only been on the market since 2012 the automaker is already working on a mild facelift for its most popular model. And it will include three-cylinder 1.5 engines.Such units have already been announced for the BMW i8 hybrid and parallel brand Mini.Spy photographers captured images of the facelfited 3 Series in Germany. IMAGE GALLERY: 2014 BMW 3 Series (SPY)Spy images reveal changes to the front bumper, modified air-intakes and LEDs headlights instead of xenons. Most modifications will be under the bonnetNEW ENGINESBMW will offer is new 3 Series with a new range of three-cylinder petrol and diesel engines. In the future, these 1.5-litre units will power a wide range of models ranging from the new Mini to the 1, 2, 3 and 4 Series. BMW may even introduce the 1.5-litre engines in its next 5 Series and i8.In addition to the new engine-range, the 2015 BMW 3 Series will be given updated driver assistance systems and comfort features such as the traffic-jam assistant derived from the 5 Series. Using a camera, the system automatically controls the brakes, throttle and steering at speeds of up to 40km/h. The facelifted BMW 3 Series, set to be launched later in 2014 or earlier in 2015, will compete against the new Mercedes C-class, Volkswagen Passat and Audi A4.