98 jeep wrangler with a 2.5 ltr 5 speed. I drove on the interstate this morning and didn't really notice a severe change to the response in power. however this evening on my way to a club, i couldn't get over 60 mph. with the exception of the lower gears 3000rpms is dificult to acheive. (typcal idles around 900rpms) in 4th and 5th gear around 2500 rpms is about as high as it will go. in addition to this while driving in 3rd gear and trying to go higher then 3000rpms the engine begins to sputter, but doesn't die. when in nuetral or with the clutch depressed the engine will respond well to changes in the gas pedal. But with resistence to the engine the above results apply. having only a 2.5 ltr its never been a power house. but i only really had a problem doing 70-80 with heavy winds or the top off (different aerodynamics.) So i'm asking for hints for what to look for, or ideas to resolve the problem. thanks for reading and any help you may offer.