in order to prove that the modified engine uses less petrol, you should perhaps do a video running both machines side by side, filling small equally sized clear bottles with petrol (enough to run for 5 or 10 minutes) to be used in place of the usual fuel tanks.
it would be better if both machines had the same type of generator attached. both machines would need to power a visibly equal electrical load, perhaps a couple of floodlights, and both would need to show an equal power output on watt meters...
if the geet system does indeed use 30% less petrol, it should run for 30% more time with an equal amount of fuel.
if you could demonstrate this it would be very interesting.