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View Full Version : Sign on trailer gate and wind drag?


walker-talker
03-16-2005, 05:49 PM
Drop gate on trailer measures 4ft x 6.25ft. The sign that I want to mount measures approx. 3.5ft X 5.5ft. Do you think I will expierence a considerable amount of wind drag and a decrease in gas mileage?

For the most part I won't be on the highway. Maybe one day a week and only approx 4 miles. Most of the driving will be 35mph to 40mph.

What do you think?

Thanks
Matt

marko
03-16-2005, 05:56 PM
Try a piece of plywood and check it out. I would think you would have no problems.

ed2hess
03-16-2005, 06:03 PM
I was thinking the same thing, so I put the sign on the back side of 2x2ft blower cage which is on the front part of the trailer. I had a cardboard one on for a while and it nearly tore it up from wind.

Precision
03-16-2005, 06:04 PM
I have to tell you that it will make a huge difference.

I drove with a trailer with no gate roughly the same weight as mine for 100 miles and got 13.5 miles per gallon

Then I drove (same truck and load) with my 5' high gate (with expand a metal) and got 10.5 miles per gallon over roughly the same 100 miles. So my drag was increased that much with a perforated substance. I can only imagine what a solid object would do.

The plywood idea is a good one.

Guthrie&Co
03-16-2005, 06:06 PM
here a trick to help you get an idea. ride down the road at 50 mph and put your hand out of the window. turn it so the flat side is facing forward. how much drag to you feel with that? now just imagine what your sign will do. my point being is that it will be alot of wind resistance

beransfixitinc
03-16-2005, 06:14 PM
Speaking of wind drag.. why aren't enclosed trailers built with a sloped roof, so as to provide downforce on the trailer at highway speed? It would seem that even a slight slope from front to back would give more control on the trailer.

LonniesLawns
03-16-2005, 06:17 PM
as far as drag -- a perforated metal gate has about about hte same drag as a solid piece of metal back there.

drmiller100
03-16-2005, 06:17 PM
because you want to minimize the tongue lifting affect due to wind as much as possible.
trailers start to whip when there is not enough tongue weight.

also, if you look into aero of it all, the rear of the trailer determines how much drag there is. if you look at missles or air planes or whatever or wings they tend to have the widest part forward, then taper to minimize drag.

Guthrie&Co
03-16-2005, 06:18 PM
as far as drag -- a perforated metal gate has about about hte same drag as a solid piece of metal back there.
thats is about the dumbest thing i have ever heard. the surface area between the 2 are worlds apart.

lpwhandyman
03-16-2005, 06:26 PM
I have a sign on the back of my trailer.....yes it does have a little drag....but I only notice it when the trailer is empty and I'm on the highway doing max speed. When it has the mower on it, I can't tell a difference. I'm sure it does cut down on the mileage a bit, but I considered it worth the extra advertising that I was getting. Either way, with a full size pickup and v10, I never did like to discuss gas mileage. All I know is I'm raising prices across the board this year, because $60 at the pump is a little much.

green acres lawns
03-17-2005, 01:10 AM
thats is about the dumbest thing i have ever heard. the surface area between the 2 are worlds apart.
Just ask any truck driver. A cattle hauler or car hauler is a whole lot harder to pull than a van type trailer and uses more fuel.

tiedeman
03-17-2005, 02:18 AM
that is one of the reasons that I have never put a sign on the back of the trailer, because of the drag and MPG.

coastallandscapesolutions
03-17-2005, 06:19 AM
A sign will cause a lot of drag. We lost almost 30% on mileage when I had a 2X3 sign on back of the trailers. I changed them to a 6 inch by 24 inch sign and it went to 2% which I considered acceptable.

PMLAWN
03-17-2005, 07:33 AM
Keep the sign low.
Wind drag has a lot to do with how smooth something is as well as how big. Yes a gate with a grate on it will tear up a lot of wind and not be as if nothing was back there. But it will be better than a solid wall.
The wind going across your trailer with all the mowers and stuff hung on it already tears up the stream so keep the sign about as low as you mowers and you should be ok.
An enclosed trailer will go through the air raiser than an open as the air will just keep getting broken up. The drag will be higher.

I am in Nascar country, The new thing is a single decal for all the paint colors and decals as it does not put all those edges in the wind to slow down a car.

Keep in mind that the drag becomes more important as the speed increases, in multiples.

Runner
03-17-2005, 10:54 AM
Too bad you couldn't paint it bold enough so that that the sign is ON the steel expando. I saw a trailer done like that that had an American flag across the back. From the distance, it really stood out.

walker-talker
03-17-2005, 04:03 PM
Thanks for all the input. I could see that working runner...if the gate was white. That was the colors would contrast more. I have my logo and phone number painted on a piece of plywood already. I was going to mount it on the side of my leaf truck, but I would get much exposure with it since I only use that truck a month out of the year. I will probably give it a try on the trialer and see how it goes.

Thanks
Matt

AuburnGuy
03-17-2005, 05:40 PM
I have a 4' x 5' sign on the back of my trailer also. I could not tell any difference in mileage or drag after adding the sign. I drove the trailer for about a year before i got the sign.

Tigs
03-17-2005, 06:04 PM
I got some signs printed for my trailer, it's a plasticy material. I was wondering how to attach them, I was thinking put it on plywood then plexyglass over the top. Any ideas?

PROCUT1
03-17-2005, 06:17 PM
ONE THING IS FOR SURE......... DONT ATTACH IT WITH ZIP TIES


Thats on my list of stupid things I have done........ :dizzy:

Guthrie&Co
03-17-2005, 09:19 PM
Just ask any truck driver. A cattle hauler or car hauler is a whole lot harder to pull than a van type trailer and uses more fuel.
yeah that is what i will do . ask some dumb redneck truck driver that doesnt know a thing about aerodynamics. i think i will bank on my experince in the wind tunnel rather than a hemorroid jockey.

walker-talker
03-18-2005, 09:38 AM
ONE THING IS FOR SURE......... DONT ATTACH IT WITH ZIP TIES


Thats on my list of stupid things I have done........ :dizzy:Funny....lol....sorry. I will add to this. I used wire ties to put on my tag, needless to say I had make a police report and pay for a new tag.

I had planned on welding some small pieces of angle iron to the frame of my gate. Drill holes in those and the plywood that I used to make my sign.

Another idea I had was to cut around the tree and down to the "progressive" and across. This would cut out a chunk about 15" X 35". The pros would be less wind drag. The cons would be, I lose advertising space (like "mowing, aerating, weed control & fertilizer") and I one that I am more worried about, would I have enough wind drag to break the tree part off. What do you think?



Matt

walker-talker
03-18-2005, 09:40 AM
Oh yeah...in case your wondering, I do have my phone number underneath my logo. Here is a photo.

Precision
03-20-2005, 12:16 AM
Drill some holes through it and mount it to the gate with round headed bolts, large flat washers (to spread the load) split ring lock washers (to keep it from unwinding) and nuts. Add locktite if you are really worried.

So long as you have enough fasteners to keep the sign from vibrating at speed it shouldn't come of or break off any part of the sign. Maybe one fastener per 9 linear inches around the perimeter and 2 in the center. I would think that would hold it very tightly.

Patrick.B
03-21-2005, 02:47 PM
Here my sign back of my trailer ....Jun17083.JPG (196.7 KB)

lawncare3
03-24-2005, 12:46 AM
because $60 at the pump is a little much.

wtf u filling up for $60

I didn't even fill mine up full and it was at $68 Gas around here is $2.27 a gallon for 87