RV wind deflectors do they work we will see

[cj99]

Ok , So as we know the current cost of fuel ( 5 to 6$ ) for diesel it is more important than 1 year ago to try and save fuel. so things I would not have bothered with due to pay back time are now on the table again.
So I have bought ( but not gotten yet ) a wind deflector for the RV ( goes on the back/top of the truck ) . I have been reading and watching videos about them and it seems a very mixed bag. some people claim 1.5 to 3 MPG while others seem to have even seen a loss in MPG.
Most of the reviews that claimed a loss were on trucks that pulled TT and I believe the issue is with the distance between the top of the truck and from of the TT, typically feet away like close to 5 ft. while on a 5th wheel the top of the back of my truck to the front of the RV is maybe 2 ft ? I have to believe they work or you would not see them on big 5th wheel trucks ( tractor trailer setups ) But most people even ones who seen little to no improvement say it did cut way down on bugs on the front of the RV. That alone has value to me and if there is no bugs then were did they go ? They had to go up and over or around the RV which kind of tells me it must work !
Now I am getting ready to travel about 2000 mile on my next trip so even if I get half of what they claim ( 1.5 MPG ) that's 200$ at 5 dollar a gallon price . This almost pays for the air deflector . And if I sold it for half of what I paid for it then I'm ahead right there.
I will try to record data and post it here. Ill do 65 MPH on flat road with it down for 50 miles or so then try it with it up and see what the old MPG gauge says .

[Grit_dog]

fj12ryder wrote:
Good idea. Lots of skeptics on here. 🙂

Lotta bull sheet too. 14mpg + towing a 5ver? Lol.
Not sure why anyone would be skeptical of that… but I consider the source.

Then there’s the folks that don’t believe a diesel dually ready to roll could be 10klbs and other who think the guys said it weighs 16k.

[fj12ryder]

Good idea. Lots of skeptics on here. 🙂

[ivbinconned]

I just now read this whole thread and enjoyed it.
I built a deflector out of aluminum for a previous truck. It looked good and for me to cut the bug issues in half it was worth it.
If I was to build another for our current truck I would use electric actuators to raise and lower it on the fly. You sure could get an instant account of mileage impact with this a feature.

So as to not start a big discussion here I will not tell you the brand or modifications I’ve done to my one ton long box but I feel good about the fact I average 14+ US mpg pulling our 13,000 lb trailer.

[cj99]

Good looking rig

[jjj]

Here is a side view that shows how far away from the trailer they are. I don't think it is too effective though. I think it needs to be closer.I think it would be closer on a short bed truck.

[cj99]

your truck loaded by itself ( wife LOL , tools , fuel , etc ) is 16K WOW that's like double the trucks empty weight !!!!!!!!!

[cj99]

I seen one yesterday on my way back from AZ to CO, it looked good but was custom. It was mounted right behind the can on basically squire tube bracing to make it level with the cab off the guy's fuel tank or toolbox. it looked good. and the plastic air dam was kind of V-nosed, it almost looked factory he did a good job. I tried to get a picture but by the time I got around to it, was took late.
His probably did better because it was closer to his 5th wheel

[jjj]

I have one,though it looks good but it really does not save me any fuel. it is too far away from the trailer to do any good, but it does help with the bugs.

[Cummins12V98]

cj99 wrote:

Michelle.S wrote:
That 20K is the trailer only, total combined Gross is almost 30K

So you're saying your truck was 10k ? A 1-ton truck or something bigger?
most 1 ton trucks are in the 7 to 8 k range loaded

My 15 DRW AISIN/CUMMINS 4X4 full of fuel, tool box plus wife and I set at 10 ready to tow. Tad over 16k loaded with the measly 6k pin.

[cj99]

Michelle.S wrote:
That 20K is the trailer only, total combined Gross is almost 30K

So you're saying your truck was 10k ? A 1-ton truck or something bigger?
most 1 ton trucks are in the 7 to 8 k range loaded

[Michelle_S]

That 20K is the trailer only, total combined Gross is almost 30K

[cj99]

Ok results are in. keep in mind not 100 accurate but as close as I could get
keep in mind my last trip same RV but from west to east ( I-40 I-70) was 7.9 MPG avg and truck gets 15.7 mpg avg empty
1st day ......................................................
leave Harrisburg PA up to I-10 ( north to ) mild hills and mountains
10.1 MPG at 55 to 65 MPH
once on I-80 headed west at 65 to 75 MPH ( 1800 RPM ) 8.6 to 9.1 MPG
2nd day..........................................................
Ohia to Illinois 8.6 MPG ( flat highway ) ( 65-73 MPH )
3rd day..........................................................
Omaha to Denver ( well Limon area east of Denver ) 8.3 MPG ( flat highway but last half starting elevation increase ) 73 MPH avg ish 8.3 MPG once I hit 4000 ft above sea level
4th day.........................................................
eastern CO south to colorado springs to Westcliffe ( 6k to 8k above sea level ) truck not overheating but running hot to maintain 60 to 65 oil temp up to 240 ish , water bouncing off of 3/4 on gauge, exhaust gas 1500 to 1800, could not get below 1200 when backing off, heavy headwind none stop 8.0 MPG.
5th day...........................................................
NO RV, south to PHX AZ, average back to 15.8 MPG at high 75 MPH
..................................................................
Final thoughts, Air deflector did work, but not enough to justify the cost. I feel I got 0.5 to 0.8 MPG gain, as for bugs bottom half of the front of the RV was clean, top half was covered in bugs.
So the product looked great and worked little, if it was 150$ or less ( what it should cost ) I would keep it. But for the $ I spent the payback time was too great. return the product through Amazon for a full refund so nothing lost.

[cj99]

Michelle.S wrote:
I have pulled the same unit, 2016 Redwood 39MB that is 43' tip to tale and pushing 20K with a 2011 Duramax 3.73 gears and current 2018 Duramax also with 3.73s, both Duallies. and have averaged between 10 to 11 on both putting 50K miles on the RV

cat scales had me at 29K. just saying

[fj12ryder]

It would be interesting to see a side view with the trailer attached, to kind of give an idea of distance from the deflector to the nose of the trailer, and the height comparison.

[cj99]

OK well its installed , here are pictures of it folded up & folded down see shared folder linked :

link here