My friend and I have almost identical, V-nosed, 12-foot, motorcycle trailers. With an open pickup bed, our mileage sucks big time. On my diesel with a camper shell, my mileage was about 20% better than with my truck that didn't have a camper shell, but I attribute some/much of this to the difference in gearing 3.73 vs. 4.30 read ends. He bought a camper shell to try to improve his mileage over what he was getting with a flat, bed cover on his truck. Worsened his mileage by no less than 20-40%. Tested in varying directions and wind conditions and he ended up just selling it as it not only wasn't helping, it was hurting. Then he towed two bikes in the trailer with an RT in the bed and got an amazing 20-40% INCREASE in mileage! It was like the weight didn't matter, that RT was breaking the wind as it came over the roof of the truck and providing a nice, slipstream for the trailer to 'snuggle' into. He's going to tow three bikes a thousand miles and for the return trip, he bought a canoe he's going to saw in half to replicate the 'bike-in-the-bed' aerodynamic effect. Any aero engineers out there with some better ideas? Or anybody found anything to increase their mileage? One of the reasons I went with the V-nose was I thought it would be an advantage, but I'm beginning to doubt the effectiveness of the V now.