We all know that the aluminum VW engine case is about 24 pounds heavier than the magnesium case. The Jabiru uses the heavier aluminum. They both use iron barrels and aluminum heads. So why is a full-up Jabiru engine 25 pounds lighter than a similarly equipped VW? Where do they save 25 pounds of weight and how do they make up for an engine case made of heavier material than the V-dub? I'm baffled.