West of El Centro you will have a winding 9 mile climb up a 6% interstate grade and then once up on top the mountains several ups and downs for about 30 miles over to Pine Valley.
From PV you will have a 20 mile downgrade that goes back and forth between some interstate type 6‰ grades and leveling out occasionally. Nothing to be concerned about at all.
The 9 mile climb up out of the desert west of El Centro is pretty steady and will keep your engine roaring all the way up to Jacumba. But it's a beautiful drive.
Up on top the mountains is Golden Acorn Casino and Travel Center as a place to take a break if desired. Food, fuel, propane, etc. Huge parking lot. But do fuel up in Yuma. Way cheeper.
Good travels.