I have gone till 140 km in a mehran but not on a straight road. I did it while coming down on sherpao bridge going towards main boulevard. The car was screaming like crazy. But 140km/h is only possibly on a slope or may be on motorway. And about the braking. It didnt slow down when i applied normal brakes, i used the hand brake as well as nomral break plus reducing the speed by shifting the gear into third and then second.
Stopping mehran after doing 140km/h coming down from sherpao bridge u must use all these three things to stop it.
1. apply normal brakes.
2. use hand brake but dont pull it all the way up or the car will roll and u would probably die. use half hand brake.
3. change gear from 4th to thrid and then to second to reduce speed
Combination of the above mentioned three ways would stop the mehran fairly easily.