What is the mileage of Tata Safari Storme on highways and City?

The ARAI has claimed Tata Safari Storme 2x2 and 4x4 versions to return a mileage of 14kmpl and 13.2kmpl. But as well know that on the highway, the driver has not to apply the brake frequently and doesn't have to change the speed and gears, so a car ultimately produces a better mileage on highways than the city.