well i have a 2wd-4wd swtich, the gain i get on MPG is only 1 extra Mile, not to much, power i can't tell. But my main reason why i have the TOD of all the time unless offroading is cuz sence i got the lift it makes this weird noise, and many here have had it or have it when you go higher then 50mph, but when i have the TOD off the noise goes away. I don't know if there is a bigger problem here then i think, but thats what i do.