i got my city's tank refilled @154km yesterday while going to lahore, it still had some gas and would do 165-170km i guess.this was with 2 people and 100% a/c (on fan speed 3) on motoway doing around 120km/h in 5th gear.
mileage depends on the way u drive and the tuning of ur car.
theres some problem with all honda cars (or may be most of them). the locks give up after a few months.my cars' trunk lock, drive and passenger lock AND also the ignition lock, all died within a year or bit more i guess.i got the ignation and driver side door's lock repaired and they are doing fine until now.but it was annoying :@
as for the check engine light issue, thats just cng tuning problems, if plugs airfilter tappets etc are fine.