Alfa Romeo’s US relaunch will finally take place at the Detroit motor show in 2014. The production version of the mid-engined 4C sports car will make its debut at the same show.

The 4C will head a range that is set to grow over the next two years to include the five-door Mito, new Spider, Giulia saloon and estate (to replace the 159 range), a new compact SUV and the new 6C flagship saloon.

The first of the new Alfas is not due to be seen until the second half of next year, Autocar sources have revealed. So the company will have to make do with the current Mito and Giulietta for at least 18 months as its sole two new cars available in showrooms.

Once sales are under way in North America, Alfa will turn its attentions to launching in the Chinese market. It had a stand at the Guangzhou motor show late last year and was pleased with the response its models received.

Autocar has also learned from Fiat Group sources that the 4C will only be offered with a dual-clutch automatic gearbox with paddle shifters. There will be no manual option.

However, the 4C’s twin-clutch ’box won’t be exactly the same Fiat Powertrain-developed dry-clutch auto used in the Giulietta TCT (see first drive, p37) because it can’t be installed in a mid-engined car in its present state. Instead, the 4C is likely to get a version of this transmission adapted for mid-engined installation.

Sources have confirmed that the 4C will be powered by a new 230bhp version of Alfa’s 1750 turbo petrol engine. In its present 197bhp state, this engine has a torque output of 236lb ft.

This is well inside the new auto’s maximum torque tolerance of 258lb ft, which means the 1750 engine is also in line for a torque increase for the 4C