For those friends who want to go karachi by road.
I would suggest two options:
2 days trip plan:
Leave lahore early morning, after fajr prayer. Try to have lunch at Mushtarka hotel before Bahawalpur bypass. Suitable Night stay is at RYK. You will reach there by 6.00 p.m
Then next day, off to karachi. Its almost 700 kms from Ryk to karachi.
3 days trip plan (ideal in my case though):
Leave lahore around 10.00 a.m. make your 1rst night stay at bahawalpur. it takes around 7 hours to reach bahawalpur.
Then next day leave bahawalpur around 9.00 am and reach sukher. You will be there I think before 5.00 p.m.
And then next day off to karachi. From sukher its around 500 kms to karachi.