The current-generation BMW 5-series (Codename: F10) will soon be due for a mid-cycle refresh.

The German carmaker is already testing a mildly reworked version of its Mercedes E-class-rival. The updated 5-series is likely to officially be unveiled at the Frankfurt Motor show in 2013.

While development of the new car still has the good part of a year to run, changes being made to the 5-series appear less significant than those adopted by the upcoming revised E-class.

Externally, the 5-series will get more heavily structured bumpers and the lamp graphics will be revised, and our sources tell us that the existing bodywork will be largely untouched. Revisions to both bodystyles are limited to a new grille, lights and front and rear bumpers.

Inside, BMW plans to provide the 5-series with the latest version of its iDrive multimedia system and a configurable instrument display already recently introduced on the facelifted 7-series.

Not much is known about the upgrades under the hood, but we can expect the engine line-up to be more fuel-efficient than the current offerings.