That's kinda my quandry... My wife and I are 5er virgins. My cousin however fulls a heavy hitchhiker 5er and told me not to put anything lightweight in the box while towing, or it'll get sucked right out of there. Wonder if that same effect would happen with the tailgate off? As was mentioned on an earlier thread, MPG variances seem to be negligable either way, tailgate up or off.

 

John,
That very issue was discussed by one of the engineers who ran tests on the tailgate up/down wind tunnel scenario. He went to the computer they were using and added a configuration something like a fiver would be, but all flat panels. He concluded from the computer simulation (not physical tests) that the wind flow definitely changed in the bed with tailgate up, but the basic bubble was still there. This would lead you to believe tailgate up is still the best. Hence, a good excuse for me to NOT spend money and NOT buy the V-fiver tail gate. The CFO was quite happy to hear the news. If you add all the various configurations of design of the nose of fivers, this could really confuse the results.

One important point to remember when towing a fiver and thinking about leaving the tailgate down, will the tailgate hit the fiver in a turn? Mine will just touch it if I am turned just right and at a slant like going into a fuel station. Another problem mentioned in one of the reports is the additional wear and jerking on the tailgate suspension wires of the tailgate continually jumping up and down when hitting bumps.

Radman - - the reports would show that mpg changes leaving the gate down when running solo is not necessarily negligable. It showed from 5 to 10% decrease in mpg. That sure seems high to me, but that's what was in the report. Watch the configuration of the bed in the truck racing series. What do they do with the bed? If leaving the gate off would help mileage and air flow, the gates would be off or open. And those guys have the advantage of putting their truck in wind tunnels for testing.

 

A) I think I can lend my support to this position, I don't like spending money at the best of times.
B) As far as leaving the tailgate down, this is not an option for me. The overhang on my fiver is such that I can't even turn a little bit, before the corner of my tailgate hits the front of the fiver. And I mean only a little bit. I have full turning ability, but when I'm hitched, I don't have enough room behind my bumper, to get into the leading compartment of the fiver.

John

 

I have the same issue here. When hooking up I drop the tailgate, backup under the hitch then raise the tailgate before hooking up.

Good discussion

Doug

 

Hey Doug,
Only four posts - - new man on the block. Welcome to a great forum. There are some really crazee people on board, but most are pretty sane.

My son is an engineer with Boeing in Everett. Lives over on Whidbey Island (did I spell it right?). We have not had the opportunity to see his new digs - - that is next year's trip. This year it is Alaska. Can't wait.

Bob

 

Who you calling crazy????? Bob...... don't even think about it.

 

HMMMMM, you been looking in that mirror again, hey.

 

Not to mention,,,,,,,,,,,,,,,,,, have you met any of the Admins in person?

BTW,,, I tow with my stock tailgate up. My thinking is, even if you removed it entirely,,,,, there is still the flat front of the 5er a couple of feet right behind the bumper,,,,, and if I was worried about that little amount of fuel consumption,,,,,,,, I would still be RVing with a bed roll tied to the handlebars of my Harley!

 

I did the same wth a heavy igloo cooler in the bed of our truck with the 5'er on. I looked in the rear view and there was the cooler stuck to the underside of the overhang. We put it inside the trailer. Next time out I removed the tailgate. I thought I could feel the difference but that could have beed wishfull thinking. But there is alot of air trying to get around, over and under the 5th wheel. I'm still not sure about it but no tailgate is cheaper than a V tailgate. To keep it short, the wind sucked one of the panels out from under the overhang on the interstate. Alluva sudden I heard a racket and saw insulation flying. There must be one heck of a wind tunnel through there with the tailgate off. It sounds like it too. Kinda rumbly without it.
Running empty? I just don't like the looks of no tailgate.

 

Guys,

I received the drag coefficient study from Professor Said Dini at Western New England College. I received it in parts and pieces and slapped it on a .ppt file. I hope it makes sense.

How can I post this data? I can find no way to attach a document from my harddrive? Lemme know.

- JyRO