Keeping the factor in mind that you doesn't stop for a long time anywhere with AC ON and mantain a speed on the average 60 - 70 KM/h within Cit, i talked to many CNG technicians and ALL OF THEM told me it would not go beyond 100 - 110. They also suggested me not to do any "Chair Chaaar" with the kit as it wouldn't help me increasing the average.
Like Aqua suggested his Saloon 1.6 is doing 125km, many people claim better average.
The real thing that matters is CNG in my car is not installed for a long time, it has completed only 7 - 8 months . . .