On the passenger side, just above the edge of the kick panel is a small silver control unit with a 4 pin plug about 2"wX2"hX3"L that is the FPCM (fuel pump control module). It is only used on ffv vehicles. And between the batery and the fender there is a dropping resistor for the ffv trucks.
Dropped my truck off a few months back for some work, and noticed on a few of the trucks on the lot there was a Flex fuel decal on the tailgate. Not sure if this started in some '07s or just the '08s. But if is new and there are pics of the tailgate, that would tell you if it is flexfuel just from an ad.
New to TT and enjoying it. Would like to know what is the positive side to FFV? The cost is cheaper but it burns twice as fast from what I have be told. Is it the politics of trying to drive down the cost of gas by having a secondary source of fuel? Or have there been changes to vehicles and they get better mileage out of the E85.