Boeing 747 vs. IO-3

I just checked that the tight fit passenger compartment in IO-3 is 75 m3 only where as the whole pressurised volume in 747 is 1645 m3. So it would be obvious to think the power needed to pressurise the IO-3 is 1/23th of 747 aeroplane's. http://www.montereypeninsulaairport.com/747specsheet.html I compare to 747 because it has similar span and 747 info is available. 747 weighs 100 times more. Boeing 747 engines produce 87325 hps. So it has power to weight ratio about 0.21-0.22 hp/kg ( which is very low compared to the speed ). http://www.aerospaceweb.org/question/propulsion/q0195.shtml In comparison RF-4 gets only 110 mph at 0.1 hp/kg; http://en.wikipedia.org/wiki/Fournier_RF-4 ASK-14 is even more remarkable; http://www.scalesoaring.co.uk/MOTOR_GLIDERS/Docs_MotorGliders/MotorGliders/ASK-14/ASK-14_Docs.html It gets 140 km/h at only 0.069 hp/kg ( same as Voyager take off setting ). Boeing 787 Dreamliner has exactly same power to weight ratio as 747 ( 0.21 hp/kg ); http://en.wikipedia.org/wiki/Boeing_787_Dreamliner Boeing 747 has better loaded unloaded ratio than the 787 Dreamliner; http://fi.wikipedia.org/wiki/Boeing_747