Also, there are no cell phone networks, no roadside assitance/police/motorway police or even and CHAI dhabbas on Makran coatal highway. The 600km from khi to Gwadar is just pure rugged beauty and a road which will lure u to floor your vehicle.
Do not travel at night, at any cost. There is only one chai hotel after 300km from khi, that too is pathetic (read: extremely bad toilets).
For me (i traveled there last summers in 2 double cabins, with locals), we took some medicines which slowed the digestion process , and carried fuel till the neck. Left around 7am and reached gwader by 2-3pm.