Originally Posted by fredm.seven
screderman you are correct. I pull a 2503S with a Pathfinder. The manual says 60 sq ft of frontal area. Frontier's probably the same.
My plan is to upsize the truck by retirement (another 2-3 years) for long haul, maybe cross Canada trips. In the meantime we camp in several Ontario parks and get to them on secondary roads all the way, farthest being Algonquin about 4-1/2 hours. Flat or hilly the Pathfinder tows fine for me when speeds are 80 km / 50 mi per hour. But a couple of times we have jumped on the 401 and the drag at highway speed always makes me get off on the first available exit.
I am not a scientist but I do believe it's the flat back end of the 2503S that really makes the difference, much more than the weight at highway speed. I think R-Pods and other back end rounded units probably are a good choice if you're planning longer / faster trips. Of course with enough truck you're OK too.
You're right that highway speeds make a lot of difference. I felt the same when towing my Roo with the Tacoma. Towing on back roads was easier than on the 401.
But it's the flat front wall that causes the drag more than the shape of the rear wall. The more vertical the wall, the more drag you have. Think about trying to walk with a 4'x8' sheet of drywall into the wind. Towing your TT is like pulling a kite through the air.
When pulling a trailer down the road, drag is affected by velocity, area of the front wall and density of the air.
2011 Rockwood Signature Ultra Lite 8293SS, 12K Equal-i-zer
2016 Ford F-250 XLT SuperCrew, 6.2L, 4x4, 6'9" bed, 3.73
2010 Rockwood Roo 23SS (2012 - 2014)
2009 Ford F-150 XLT SuperCrew, 5.4L, 4x4, 5'6" bed (2012 - 2016)