Fiat is re-launching the iconic Alfa Romeo brand with the new mid-engined, rear-drive Alfa 4C compact sports car. The stunning new lightweight model, seen here officially for the first time ahead of its Geneva motor show reveal next month, will be the first of a range of new Alfas over the next few years, and will spearhead the Italian firm’s return to the US market. The production two-seater 4C coupe, complete with its carbonfibre chassis, returns to the Geneva show two years after a concept of the same name was introduced. Power for the new sub-1000kg model, which is tipped to cost less than £50,000 when it launches in the UK at the end of the year, comes from an all-aluminium turbocharged 1.7-litre engine. Alfa is keeping exact technical details of the 4C under wraps until in Geneva on 5 March, only confirming figure being a power to weight ratio of less than 4kg for every 1bhp. Information leaked by Alfa dealers in Switzerland suggests the 4C will be offered with 237bhp in its initial launch guise, which would mean the 4C would weigh 950kg, a figure that’s likely given the concept weighed 850kg and a production-spec interior is now fitted. A 0-62kph time of around 4.5sec has been mooted, with a top speed limited to 250kph. The four-cylinder engine known as 1750 TBi is familiar from recent Alfas including the Giulietta, but the block is now cast aluminium instead of iron, saving around 25kg. The engine gets direct-injection, MultiAir dual continuous variable valve timing and a new scavenging system that “gets rid” of any turbo lag. Bespoke intake and exhaust systems have also been developed for the 4C. The result of these technologies is an engine with the potential performance of a 3.0-litre six-cylinder unit, but with the fuel economy and CO2 emissions of a smaller four-cylinder engine. The 1742cc engine powers the rear wheels through Alfa’s own twin dry clutch automatic transmission, adapted from its application on the Giulietta and Mito. The transmission has a sequential mode that can be controlled through paddle shifters mounted on the steering wheel. No manual option will be offered. The 4C is just less than 4000mm long, is 2000mm wide and 1180mm high. The wheelbase is 2400mm in length. These dimensions place it between a Lotus Elise and Evora in length, height and wheelbase. Underpinning the 4C is a carbonfibre monocoque chassis, something previously reserved for supercars like the McLaren MP4-12C and only seen on a small number of sports cars at this price. Tub-mounted aluminium frames carry the 4C’s running gear and engine, with the front assembly carrying a double-wishbone, coil-sprung suspension set-up, and MacPherson strut suspension features at the rear. Alfa’s DNA driving mode selector also makes an appearance on the 4C with Dynamic, Natural and All Weather modes now being joined by a new track-focused Race mode. Production of the 4C will start in the summer at Maserati’s Modena plant, with 2500 units set to be the annual output from 2014. Europe and North America will get 1000 units per year each. The remaining 500 being distributed around the rest of Alfa’s global markets. This production run will include the other models in the 4C’s range that the Swiss dealer source revealed. In 2014, a track-only Racing version of the car will be introduced, with a road-going Stradale version of that car set to follow with 266bhp. A convertible will crown the line-up later in 2014.