VW is struggling, but thanks to Audi and Porsche it could have a great 2015

Volkswagen has been struggling to build up its brand in the the United States while also competing with General Motors and Toyota globally.

However, VW also controls Audi and Porsche, two of the biggest luxury brands in the world.

And Porsche and Audi are anything but struggling these days.

As a result, Volkswagen has decided to to stick to its guidance for operating profit after posting record earnings last year on double-digit gains in Audi and Porsche sales.

Europe's largest carmaker said on Friday the group operating margin could come in a range between 5.5 percent and 6.5 percent, same as last year's projection.

The German group raised its forecast for revenue, saying it could exceed last year's record 202.5 billion euros by as much as 4 percent.

That's a pretty satisfying bit of guidance for VW - evidence of how important luxury brands currently are to the world's automakers.