Vr6's and Vr5's Crank pins (or "throws") are "offset" by 15° to compensate for the 15° V angle of the block.
So a Vr6 is actualy an inline six (pistons 1 and 6, 2 and 5, 3 and 4 reach T.D.C. at the same time causing even firing pulses).
Same theory goes for the VR5 (except the pistons idividualy reach T.D.C. every 72°).
In the pic below, if you look at the crank throws (1 and 6 for example) they are just BARLEY offset....

<img src="http://www.eurospecsport.com/Images/engines/vr6crank.jpg">



NOW, I bet you guys didn't know this, but the Audi V6 is a 90°V instead of a 60°V (the way it should be to create even firing pulses), so in order to compensate for the "incorrect" V angle, the crank throws are "offset" by 30° enabling 2 pistons to reach T.D.C. at the same time!!!
My guess for using the 90° angle is for compact packaging and a lower hoodline.
See pic below, and you'll see what I mean!!

<img src="http://www.eurospecsport.com/Images/engines/!v6crank.gif">

<img src="http://dtwaudi.com/images/smiles/owned.gif"> <img src="http://dtwaudi.com/images/smiles/smilie_thumbsup.gif">

The height of an engine is rarely a problem. It's the width that usually matters. That's why VW uses the VR6 instead of the V6. Because the VR6 has the small angle, it can fit into a GTI or Jetta the wrong way (transversely). If you try to put a V6 in there the wrong way, it'll be too wide.