Two powertrains will be available: a 3.5-litre petrol-electric hybrid and a 2.2-litre diesel engine developed with Daimler.
The 3.5-litre hybrid produces a combined power output of 359bhp and is expected to get from 0-62mph in less than 5.5 seconds. It has a seven-speed automatic gearbox and will be available in either rear-wheel-drive or all-wheel-drive versions. Average economy is a claimed 45mpg with CO2 emissions of 145g/km.
The 167bhp 2.2-litre diesel will come with either a six-speed manual or a seven-speed automatic gearbox and will be offered in rear-wheel-drive form only.
Performance figures haven't been confirmed, but it's expected to get from 0-62mph in less than nine seconds, with a claimed average economy of 64mpg and sub-115g/km CO2 emissions.
There's plenty of technology on board, too. Infiniti's direct adaptive steering allows the driver to tune the steering to match their preference, while the active lane control system is the first to be connected to the steering rather than the brakes.
Inside, Infiniti is promising class-leading rear legroom and an environment that will offer high levels of comfort for all occupants with the help of seats inspired by US space technology.
Pricing for the Q50 has not been confirmed, but it is expected to compete with the 3 Series. The Q50 will go on sale in Europe in the autumn.