Jeepete, I'll ocassionally get the rpm's in excess of 4K climbing the mountain slope on both the east and west portals of the Eisenhower Tunnel on I-70. I really made a mistake purchasing the '05 Unlimited with an automatic transmission; the tranny will shift to lower gears as the grade changes during the long steep climbs. When the tranny shifts down, probably from third to second, the rpm's will seriously jump to just under 5000 rpm's! It's a constant battle during the long climb to find a throttle position that will keep the engine rpm's over 2000 and under 3000 rpm's, and almost impossible to maintain the required minimum interstate speed. Checking the engine after these climbs where the engine rpm's exceeded 4000 rpm's, I found engine oil leaked out onto the valve cover at the top fittings.
Nowdays, I simply attempt to get a good run at the slope and then move over to the right with the tractor-trailer rigs with the flashing low speed warning lights! This automatic tranny is a major inconvenience in the mountains! Are you sure there ain't no way to increase the 4L's horsepower? <img src="/forums/images/graemlins/lol.gif" alt="" />