about fuel efficiency a good cuore will give u 13-14 in city and 20+ on petrol. it is reliable for long and short trips. its road grip, handling and braking is awesome. about AC it is good. performs satisfactory when car is moving but trips when not. running cost is lower than mehran. parts r available.
Like all used cars, if abbused, will give u problems.
compared to mehran, interior and build quality is superior.
I own a 2005 cuore and I love it. for common problems and information check cuore fan club where fuel consumption etc are shared by nicely maintained rides by senior members.