bhai l'd suggest you to go for CNG if available because Punjab ma tw ne milti.
CNG problem karti new wali cars ma, un k valve kharab ho jaty especially toyota 1.3 vvti engine k.
Khyber ma aesa masla ne ata, I've used more than 65000 km and about 35k km drive was on CNG, I stopped bothering about CNG when availability became scarce in Punjab. The same car still chirps its wheels while shifting to 2nd at 40+ kmh speed. Maintenance routine was caltax 20w50 every 3500km and air filter change every 2nd oil change.
Khyber is very economical on CNG, make sure it is installed properly, e.g. safety factors, switching electronics, venturi, blocking of air filter & distributor is advanced. The performance difference will be bearable.
