The GM 2.2 I-4 "Iron Duke" only put out 93hp, I know, I had the same motor in my 99 S10.I totally agree...IF the weight difference between CF and Aluminum is pretty close. Certainly not worth the price difference, IMO. Upgrading to aluminum, might be worth it...maybe.
Just from my own experience...I had a '94 GMC Sonoma with an "anemic" 2.2L engine (about 130hp). I upgraded the wheels from, IIRC, factory 205 70 15" to Michelin 225 65 16". The overall tire height was identical, but the weight definitely increased by a few pounds. The first thing that I noticed was acceleration suffered. Highway mileage didn't really change, city...a bit. I had driven the Sonoma for over a year and 30K miles before upgrading, so had a pretty good feel for what was normal.
Your results may vary.
You would never have the air on when you had to go up a hill.