In my opinion the only way to get use out of an AOD economy wise is to use EFI. If you lug a carbed engine it will not get good mileage. I once had a 351W in my 71 F100 with an AOD and 3.70 gears. cruising around the country side it was pretty much lugging all of the time. I never could get over 13 mpg with it. Tried 3.25 gears and it was worse. I didn't have any other gears to try. Lugging a carbed engine can open the power valve in the carb a lot more than is should be is all I can figure. I kept my rpm's down on the interstate which I liked but even running 65 or so it still felt like it was lugging all of the time. I think the only way to get a real benefit from over drive is to be using an efi set up I pulled all of that drive train out and dropped a mild 460 in there with a C-6 and 3.25 gears and can average around 15 mpg. clint
Cdeal - your experience is one of many. That's why I try to talk people out of using the AOD unless they are running very low gears.
