New to cross country towing

230/2:30 rule applies for an enjoyable trip...stop at 230 miles or 2:30 p.m.

Working folks have different driving numbers than retired. I've driven ten hour days towing and I'm fine but I don't like to do that more than two in a row before I take a day of four hour towing with sight seeing or a full stop.

You should not expect to get to Tucson from San Antonio in a day. The 18 hour trip will take at least 20 hours towing and probably more. There isn't much between El Paso and Tucson but I would look for a place to stop half way.

What is your tow vehicle? The climb is real going in to San Diego and often windy as well. That will make a difference. And gas up in Yuma before gas jumps 40 cents per gallon.

I make a similar trip twice a year, Las Vegas to central Texas. I allow at least 3 days pulling a small trailer. Now, I've seen just about everything along the route so allowing time for sight-seeing is not a problem. I usually start early in the morning (7:00) and stop around 3:00 in the afternoon. Now if your wanting to make the trip faster then 3 or 4 days, fly.

Cross country driving-
1. driving 4 hrs. per day= normal comfortable RVing driving
2. driving 4 to 6 hrs. per day= pushing the limits of being comfortable and early signs of sore butt:)
3. driving 6 to 8 hrs. per day = sore butt, stiff neck, grumpy passengers and dreams of warm shower and cold beer:)
4. driving 8 or more hrs. per day = torture marathon for what purpose or why not just get a plane or train reservation and avoid #'s 2 and 3.

What are you pulling it with?

Is this for an enjoyable RV vacation or are you just trying to set a record? We typically travel about 350 to 400 miles per day. After you factor in fuel stops, bathroom breaks, meals, setting up and breaking down camp, and some sight seeing the day is pretty well done.
If you're driving a gas truck don't expect more than about 9 MPG so you'll need fuel every 300 miles or so.