starting here: 560km per kilo
Kerosene has about 0.93 times as much energy by weight as gasoline
gas weighs 6 lbs/gallon
energy wise
1kg Kerosene=1/0.93=1.08 kg of gas
1.08kg of gas = 2.38 lb of gas
volume wise
2.38 lb of gas /6 = 0.4 gallons
560km=347miles.
so 347mi/0.4 gal =
867 MPG FTW!!! 
EDIT: fixed missing kg to lb conversion
DOH: the rocket in question uses Kerosene, not hydrogen!