Installed BellTech 2" dropped ball joints and 2" blocks yesterday. When I had it aligned, I had them set it with minimal toe-in. I'll be interested to watch my FE over the next few tanks. It does seem to roll a bit freer, but we all know how unreliable "butt dynos" are. We feel what we expect. Time may tell.
got any pics? i droppe dmy s-10 2". with same componets. didnt seem to do too much (if it did it was less than 1mpg...) i did it more for the look than anyhting. i plan to go another 2" cuz it still looks kinda high to me. most i can go is 5/6 but that gives a frame to road clearance of about half a popcan.
No pictures. I rationalized I was doing for aero--but every car I've ever owned has been lowered. That goes back to the early Sixties. The Colorado can't go much lower without eliminating most of the suspension travel. The inner fender panels (steel) are about even with the top of the wheel opening. Requires surgery to go much lower or a greater tolerance for a bad ride. Next will be a grille block and maybe a partial bed cover.
I just tried a partial bed cover this weekend in my Colorado. My Scan Gauge does not account for all of the engine off coasting I did, but even so it showed 35 mpg over a 210 mile trip!! I also had my grill blocked off too with duct tape (temporary till I can block it off the way I want to).
In principle, lowering reduces the amount of air getting under the truck. By covering more of the front tires it makes a small reduction in frontal area. The FE effect will probably be minimal. I've just always had lowered vehciles.
The partial bed cover was something Gale Banks worked out when he set a speed record at Bonneville with a GMC Sonoma in the mid '90s. He found that covering only the back half (about) of the bed reduced drag more than a full bed cover.
Don't forget that lowering also increases the speed of air flow under the vehicle. It is possible to increase drag by lowering if the underbody is particularly dirty. Lowering in combination with a belly pan is the best bet.