There are lots of factor involved for calculating fuel efficiency let me share my experience
1. Cylender Size = 40L (Appx. 6 k.g. Gas Filled)
2. Mehran VX = Model 2006
3. with 2 persons (driver + 1)
4. with 28-30 Presure in tires and with good alignment, New air and oil filter
5. Without AC
6. Average Paddels Push
In City:
it Gives 85 - 100 km per 6 k.g Gas
Note: when i use to drive with low RPM and with less Push on accelator the average is increase towards 100 but on rash drive it gives even 80-85
ON Highway Motorway:
on speed 90+ and bad use of accelator it give 110km to 120km maximum. (6kg Gas)
But I tried 3 4 times i drive with low push on accelator and speed less then 70kmph and i got exceptional milage arrond 155km per 6 k.g. but driving at 70kmph on highways/motorway is too slow
so the driving style is much matter