The 4 Series BMW was released in 2014 and are a range of coupé, fastback, and convertible models. The 4 Series stems from the 2-door models originally from the 3 Series, which BMW decided to move into a separate series. The models are in their first-generation and are powered by turbocharged petrol and diesel engines with 3 cylinders, 4 cylinders, and 6 cylinders.