Yes, the road is straight between the base of the mountains to the Saline Valley road. There is nothing technical about the road (unless recent flashfloods have done some remodeling), but the trail is littered with rocks and some sand.
Rental SUV? If your own rig, how many plies tread? Many OEM street tires, if you got this far from pavement without a flat tire, will be challenged. And if you continue on up, I can guarantee tire failure. Even larger tires like those on pickups and SUVs. If it’s your rig and you have LT rated tires with a minimum of 6-ply (better yet 10 ply) treads, you’ll likely do OK.
Don’t air down street tires. The sidewalls will bulge, exposing them to sharp rocks. Flats in the treads can be plugged, but not torn sidewalls. The safest tires to air down are light truck rated, 3-ply sidewall tires like B.F. Goodrich All Terrain T/As or similar.