Ok so starting on my trailer this week it will end up the same roof hight as my TV GX470. I am a surfer and alot of my small boards live in a cubby I have 2 boards around 7 ft that I designed a space for in the trailer but they take up alot of storage room. How much drag would throwing these on the roof in a tule box cause? My truck gets like 15MPG with the V8 and I have no Idea how bad it will be towing a 2200 lb trailer. What are your thoughts. If I get 11 or 12 with the trailer and it wouldnt change much I would just throw them on the roof. I only have a max air fan going up there currently.