LetThePoniesRunFree

I bought my car used in 02' and it has never had the lower front air deflector on it. It's the piece that attaches to the lower radiator support and deflects air upwards into the bottom of the radiator. How well does this deflector aid in the cooling of the car? Has anyone taken theirs off and noticed an increase in water temp? I can only imagine Ford put it there for a reason and I should probably put one back on it.