I´m interested in hearing what people think is the best/most scenic road fraom San Diego to Phoenix.

Currently I´m thinking of five possible routes which are (from the most southern one)
Highways 8, 78, 10, 40(route 66).

The thing is that we will be on a road trip and would like too see as much as possibly while travelling across the lands. Since we would like to visit SD Wild animal park route 78 seemed like a natural choice, but know I´m not so sure anymore since most guides says imperial valley/Salton Sea is immersed in intense heat during the time we will be there (September) so I could use some advice on what route to pick.

thanx in advance.

I actually did this last August. We went up to Grand Canyon National Park (via the trains from Williams). The scenery on 40 was nice but nothing overly amazing. Route 66 is always a fun one to go down, though quickly it gets a bit sickeningly touristy. I would mostly recommend hitting up the Sonoran Desert, and driving/parked at sunset.

Any of those routes will be immersed in intense heat in September. It's going to be HOT.

So, travelling to the desert areas in September wasn´t that good of an idea as we thought from the beginning as it seems like we´ll be needing lots of barrels of water with us just to survive the trip That really makes us feel comfortable with going deep into the deserts...lol

Basically it doesn´t matter heatwise what route we will take since all routes will be extremely hot in September. Then we might take up on our original plan on route 78 since we plan on going to Wild Animal park.

What about Joshua tree? Anything you guys would recommend?
Without any sense of distances/travel time in these parts it seems like it would be very much possible to see Anza-Borrego, Joshua tree and Sonoran desert in 2-3 days?!
I realise it would be a tight schedule, however in previous comments it sounds very unlikely that we will be spending much time outside of our air-conditioned rental

Except mentioning the obvious (bring water, cover skin, wear hat etc etc) is there anything we should think of travelling through some of the hottest places on earth?

78 will probably be fine.

We used to go from San Diego to Phoenix in, hmmm, about 6-7 hrs I think when we lived in San Diego. I honestly don't remember the route we took. I think we went through Anza-Borrego if that helps. But I probably didn't like any of the routes since I don't like the desert, lol. I'm sure 3 days would be fine. Make sure you map out your overnight stops.

If I were you, I'd get a case of water to take, just in case you get stuck in the middle of nowhere...people have died (I remember a report last summer) from not having enough water with them when their car broke down.

Don't forget sunglasses and sunscreen! And never wait 'til the last minute to fill the gas tank!