Fifth Wheels

potter water · Posted: Wed Sep 07, 2011 1:20 pm Post subject: Fifth Wheels

Fifth wheel and bumper pull RV's are hard on tow vehicles in another way. The total "wetted area" wind resistance is pretty high. Unlike the CD that is pretty streamlined.

I must now confess that I'm not a flat lander and most of my towing of 5th or boats is up and down hills from sea level to 7000 feet. However, I've driven a diesel pulling a fifth wheel back to Cape Kennedy across the flat lands against 35 mph headwinds and was sure someone had attached a huge anchor to the bumper. Head winds do a bigger number on MPG than flat-land towing weight with higher wind resistance trailers.

Nuff said.

thataway · Posted: Wed Sep 07, 2011 2:17 pm Post subject:

True, but it also depends on the tow vehicle, and if they have an air spoiler. An example of this is that the Honda Pilot is is rated to tow 3500 lbs house trailer and 4500 lbs boat. However, the C Dory is more wind resistance than an center console or dual console boat.

If I tow a boat behind my RV (12'6" high), there will be far less wind drag, because it is in the wind shadow of the RV.

JamesTXSD · Posted: Wed Sep 07, 2011 4:18 pm Post subject:

Having towed boats and our current 5th wheel (high profile), we find a head wind to be WAY more of an effect on fuel mileage than weight or terrain. And for some reason, we spent lots more time towing into a headwind than any other direction. Rolling Eyes

Jack in Alaska · Posted: Wed Sep 07, 2011 4:36 pm Post subject:

One would think that that head wind tail wind thing would equal out over time. But it just seems like head winds are way more prevalent than tails.
Just like walking to school in the old days. It always seemed like it was uphill both ways.
I tow my 7000 lb. 26' CD as well as my 14,000 lb 5th.whl. with the same truck. On flat land the boat slips through the air very easily but that big old flat fronted 5th.whl. seems like a stone behind.
My truck (RAM CTD dually) gets 18.7 mpg empty, 14 mpg with the boat and 11.5 mpg with the RV over similar road conditions. That makes choosing the straightest, flattest route very important particularly with the RV. We are making that choice next month on our annual Anchorage to Phoenix trip. My wife says she gets tired of the same route but it is the most economical way, very important with $5/gal diesel.