Re: what gas mileage does you colorado get???
I have a 2005 3.5L crew cab with AEM Bruteforce CAI, Borla muffler, Gerry's tune, 20" wheels, over 600 lbs in the bed and a SnugTop SL tonneau cover.
My best 434 miles with an 18.5 gallon fill-up driving back from Las Vegas so that's looking at 23.46 mpg. There's a 4000' elevation change and I was driving around 85-100+ mph most of the time.