@hummayun, bro, there is no comparison between the fuel average of 4x4 jeeps and those of cars. a 660 cc pajero mini gives 10-11 kms/L as u have mentioned, if u check out some bigger 4x4 jeep like 4.2L multivalve land cruiser, its give 3-4 kms/L. Its all about transmission, the gear ratio. Like u told about ur coure's average, if u take off pajero mini's transmission system, including 4x4 trans., and put coure's 5 speed manual trans. on it by doing lots of alteration, u will surely get above 20 km/L from pajero mini as well... but it wont be a jeep anymore that is supposed to speed thru deserts and mud.
I hope U got wat i mean to say 