I have three 4x4s, and the mileage is not as bad as that.
The smallest engine is a 4 liter six, and it gets about 5-6 kmpl in the city and about 7-8 kmpl on the highway. The body is shaped like a brick, it is nearly 14 years old and has over 165,000 km on the odometer.
Its worst mileage was 4.2 kmpl while towing a 2500 lbs trailer up mountain grades between 4 and 8 thousand feet ASL at speeds over 140 kmph, with the accelerator buried into the floor for hours.
And it does that with oversized all terrain tires and a roof rack. And I do not drive like a little old lady going to church. 
