Yes you are right I made a mistake. Now I have cross checked from my khattas and yes it 470 kms. But in that case the journey will be of 8-9 hrs so add 3 more hours to my estimate. and it comes out be 20-24 hours.
Here is my experience
First trip lahore to sukkur in 15 hours because wasted a lot of time in multan and lodhran as it was first journey so had no experience. Sukkur to karachi 8 hours Total=23 hours. Return journey karachi to hyderabad 2.5 hours hyderabad to sukkur 6 hours sukkur to multan 9 hours karachi to multan 18 hours. Multan to lahore 5.5 hours total=23.5 hours
Second trip Lahore to sukkur 13 hours this time did not waste time in multan and surroundings, sukkur to karachi 8 hours. Total 21 hours
Return journey karachi to hyd 2.5 hours hyderabad to ryk 9 hours ryk to lahore 12 hours(stuck in traffic just 20 kms short of lahore for 1 hour) total 23.5 hours
Third trip Lahore to Ryk 9 hours, Ryk to karachi 11 hours total 20 hours
Return journey karachi to ryk 12 hours( A lot of time wasted on super highway due to Nato containers occupying all 3 lanes)
RYK to lahore 10 hours stuck in rain just around sahiwal so total 22 hours.
All 3 trips same driver same car. First trip was in july 2011 second in march 2012 third in june 2012. Minimum time consumed 20 hours maximum time consumed 24 hours. Divide this figure by 1300km. maximum average speed 65km/hr and minimum average speed 54 km/hr. Considering the road conditions, the traffic, refuelling stops at least 6-8 if travelling on CNG and 2-3 if on conventional fuel. 10-12 toll plazas, stops for number 1. I dont understand how people manage it faster than that by remaining in limits. Yes my maximum speed was around 105km/hr slightly above the limit