These are the latest images of the BMW 5-series facelift, which has been spotted cold weather testing in the Arctic circle. A production version is likely to make its public debut at the Frankfurt motor show in September.

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 new E-class. 

Externally, the bumpers are more heavily structured and the lamp graphics revised, but on the evidence of the prototypes caught  testing, the existing bodywork is 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. 

On the engine front, the twin-scroll turbocharged 3.0-litre in-line six-cylinder petrol engine in the 535i is set to gain an added 14bhp, lifting its reserves to 316bhp in the new 540i model. 

The twin-turbo 4.4-litre V8 petrol engine in the 550i is also expected to get added firepower. Munich insiders have already confirmed a 43bhp increase to 444bhp.