MORE: Click here for all the details on the new naming system.
Spied testing in recent months, the 2013 Q50 sedan will be larger than its predecessor, with power in the flagship model expected to come from an updated version of the existing V6 engine.
A four-cylinder engine, sourced from development partner Mercedes-Benz, is also expected to be offered in some markets - likely replacing the 2.5 V6 in the current G25.
It's unclear how Infiniti will set variants in the Q50 range apart, with the numbers in the new names "representing hierarchy within the range", rather than engine capacity.
One possibility is that an entry Q50 variant would wear a Q51 badge, with higher-spec and more powerful models taking Q52, Q53 - and so on.
For now, we must wait until the new sedan's unveiling in Detroit next month.