I drove from San Jose to Dana Point (North CA to South Ca). Upon reaching interstate 5 my 70mph speed was set to a sudden halt. It is basically a 5500 foot climb over several miles. It might be even higher, but thats the sign I saw along the climb.
I had no extra weight other than a suitcase and my passenger.
I had to downshift to 4th gear to maintain it at 50mph, but soon after (3min) I had to drop it to 3rd to keep it going 40 to 45mph. That was the best the jeep would do. The rpms were around 4k.
I have 33's, 4:88, and 4in superlift with factory soft top.