Never trust the media... I suspect that this article is slightly misleading regarding the weights.
Either SAAB have managed to halve the empty weight of the E variant compared to the previous versions of the Gripen... or maybe the writer of the article has confused lbs and Kgs when discovering a 20% headline grabbing number (apples and oranges indeed!). Even for a plastic aircraft, an empty mass of 3 tonnes would be amazingly light if the max take off weight is above 16 tonnes - the RM12 engine weighs in at over 1 tonne by itself! I suspect 'empty air frame weight' does not equate to dry mass (no engine, no avionics etc I suspect)...
Edit - ninja'd!