I travel along the country because of my Federal cases.
I go often, or used to, to Zapala, Neuquen and Gral Roca.
My advice is:
0. Check the oil and tires before driving. Those cars usually are without proper maintenance.
1) Start always to drive at nigh; The main danger are trucks. They go to sleep at 10 PM. Sleep every 3/4 hours. Feel safe to sleep at the car at gas stations at Rio Colorado, before BB and 3 Arroyos.
2) At Rio Colorado before the bridge, full your tank, this is the last gas station with discount for living in Patagonia. Just after crossing the bridge, you have a decent restaurant on the left. Only go to YPF for gas.
3. Go to Bahia Blanca. Few kilometers before BB there is a YPF brand new gas station on the right. Use it. You can lunch there.
4. No matter what the GPS route, avoid the port. It is very broken the road and it is dangerous.
5. If you are tired you can sleep in BB but the best if to do it at Tres Arroyos (always use National Road 3), where you have a clean hotel on the road on the left. You also have an YPF on the left.
6. When you are arriving to Cañuelas be very careful not continue by NR 3 neither by BAR 6 because they go to Laferrere that is the ugliest you can find. After the railroad take to the right at 202 and you get the highway. Be very careful because is under construction the first few kms.
7. Do not eat vegetables during the trip. They do not have tap water to wash them.