I wonder why? I have an '08 F-150, 5.4L. 3.55's, 4x4, xtracab and it tows just fine. I don't think I've towed more than max spec and it seemed to have enough power. 10-11 MPG while towing but, that didn't suprise me at all. I definitely don't try for high speed or quick starts off the line, just need the power to merge and keep with traffic, which it does OK.I had a new '05 150 Supercrew Lariat, 5.4, 3 valve,3.73 gear,4x4, that was without a doubt, the worst towing truck I've ever owned. I'll grant you it was a "cute" truck, but hated to work. I averaged 17 mpg on the highway, empty, but hook a 2000lb. snowmobile trailer on and it went to 9mpg;don;t even ask about pulling the 4000lb pulling tractor on an 18" Bri-Mar tandem x equipment trailer. I kept that POS Ford 18 months and traded it.No more Fords for me, except possibly the v-10