I think the devil is always in the detail. The Ford Ecoboost engine had a tremendous write up in the press. Carried to Detroit as excess baggage, footprint no large than an A4 page.
All unfortunately completely untrue!
The excess baggage engine actually is marginally smaller than the unit is replaces - its footprint is actually larger than A3! Even better its dry weight is over 200lbs, so it must have been a robust handbag the chap was carrying(?)!
So the Ecoboost is somewhat lighter than the engines it replaces, it is somewhat smaller than the engines it replaces - but the Rotax 912iS is significantly lighter and more compact than the 1.0 Ecoboost.......