I was in the same situation you are in. I went with the V10. I picked up my special order on 6/25/01. It is a 2001 F250 Crew Cab Short Bed 4X4 V10, Island Green with Silver. I got it to tow a 28 foot traval trailer that weights 6500 lbs. My first fillup w/o towing gave me 12.77 Miles/gal. 2nd fillup w/o trailer got 13.94. 3rd, after towing trailer 311 miles gave me 9.32 m/Gal. 4th. fillup was today after vacation driving and towing the trailer home gave me 10.96. This is with no filter changes or exhaust changes. Just straight from the factory. The truck now has 1065 miles on it and i love it. It towed like a dream, and that is why I got it. A PSD would give you around 20 M/Gal so I have read, but it cost $4,000 more. Good luck on your decision an let me know what you decide on.