He's right, O/D does slow the car down. I'm limited to about 110 in O/D and the second I click it off it hauls ass.

I keep saying this, but "The overdrive in our cars is to SAVE FUEL ONLY"

I think it has something to do with the tranny being allowed to slip at a certain temp while in O/D, but when you turn it off, everything locks back down and puts the power to the road. If you have a gauge you'll see your tranny temp is sky high in O/D at 100mph.