I don't know if you'll be able to get 22+ mpg and tow 3000 lbs comfortably and have 4x4 with too many vehicles. I've been able to get around 18-19 mpg with my short bed reg cab 01 Z71 on highway trips. With a manual transmission and upgrading to electric fans from the factory clutch fan you might get close to 20-22 mpg. I don't think the V6 pickups will be able to tow 3000 lbs easily and you would probably still need a manual trans to get the 22 mpg. Maybe a V6 pickup with a supercharger will be able to tow and get the highway mpg, but then you might have trouble staying out of the throttle.
