What would be the mileage of Hyundai Accent Petrol and LPG variant?

Hyundai Accent Petrol has got a 1599cc 4 cylinder engine which can produce 101 bhp @ 5800 rpm against a torque of 14.4 kgm at 4500 rpm. The car has got a top speed of 181 kmph and gives a mileage of 11.0 kmpl on highway. On the other hand, Hyundai Accent CNG variant has got a 1495 cc, 4 cylinder engine which is capable to produce 94 bhp at 5800 rpm against a maximum torque of 124 Nm at 4500 rpm.  This can deliver a mileage of 9km/kg in city and 13.2 km/kg on highway.