Wind Deflectors

[Chillout]

Having read a thread regarding miles per gallon, I was wondering if anybody has used a wind deflector, one fitted to the car roof to deflect wind from front of caravan. Have not seen any in use for some time. Do they still make them? Do they work?

[Lefthand Down]

There have been a few topics covering this and it will be interesting to see if anything new emerges.

[David in Cheshire]

I bought an Aero Plus wind deflector a couple of years ago for about £75. I had some faith in the principle having used a much cruder looking metal plate some years ago that did "seem" to help with wind resistance and the fact that HGV's are all fitted with a device of some sort. I tow with an estate car that enabled me to fit the deflector as far back as is possible and much further than could be achieved on the roof a saloon. The AeroPlus has 3 angle settings and I tried them all, using each over a mix of motorway and normal roads for at least 200 miles on a journey to the South of France and Spain, I found no savings whatsoever in measured fuel consumption and no other advantage apart from keeping the front of the van clear of insects

IMHO money down the drain

[shipbroker]

David that was my findings about 25 years ago. .........there was one car/caravan overturned on Mount Grace Bank on the A19 about 20 years ago ( this is not a particularly steep hill) and the findings were that turbulence from the Windjammer, as they were then,had caused it. .........

 

I only know one person who still uses one and I believe it is an inflatable wedge. .

 

geoff

[WispMan]

Sounds to me like a great thing to sell but useless to own!

[Paul_B]

I always noticed a difference when not using the windjammer and it wasn't for the better, there was a marked improvement when driving into a headwind when using one.

 

However cars & caravans nowadays are more streamlined so I doubt if we would notice a difference using one. I think if they removed the drag from caravans & went back to the rounded rear this would make a bigger improvement.

[david 1220]

Hi,

​Years ago we had a Austin maxi & sprite ( C. I. ) caravan. we found that our home made wind deflector made a difference.

​Moving on to now - made a wind deflector for our present rig. having fitted it and done a number of runs with it i found ----no difference ! I can only conclude that with the present aerodynamic shape of both car and caravans ( well most- theirs one make that has a profile of a brick ! ) that things are as streamlined as its possible to get. Theirs one area were they do have a benefit-- in deflecting items thrown up by other vehicles ( motorway ) when we heard something smack our wind deflector we use to say -that's another one saved ! ( front window - dint's in the front ? )

david

[Ldsundance]

I have one but I have mixed feelings as to whether it gives any fuel savings, it might make my outfit a bit more stable but its hard to know, we really need someone with a wind tunnel, to see the wind actually flowing, it would probably be me more benefit if you towed a flat fronted van

[Gordon]

I found no savings whatsoever in measured fuel consumption and no other advantage apart from keeping the front of the van clear of insects

I still own a Windslammer from years ago, but I stopped using it as like you I found it made little or no difference to the fuel consumption, although it must have made some change to the aerodynamics as like you, it did keep the flies off of the front of the caravan. It fitted on the roof guttering, and so would not be compatable with many current car designs.

[screenman]

Do they not push the back of the car down?

[Chillout]

Thanks for all the comments regarding wind deflectors. I am assuming they do not work so good, like Ldsundance suggested one designed in a wind tunnel may work!!! Also perhaps the caravan manufacturers should also use a wind tunnel to help wind resistance and drag when designing new caravans.

[david 1220]

Hi, At the risk of causing uproar over the safety angle my late brother ( and friends ) came up with the following ,--

​Hitched caravan to car and fitted winslammer then proceeded to local motorway with friends in another car. On reaching the legal max ( 50 m. p. h. in those days ) the friends pulled alongside the brother as he drove in the inside lane

 

Brother then oporated his windscreen washers -the spray fom them hit the wind deflector and showed the airflow over the deflector & van ! They did a couple of trips to get the angle right and then locked up the bolts---

 

Now i am sitting back waiting for the ( road safety ) flak to arrive !

david.

 

P. S. A friend took his car/ caravan to the garage and used the spray from the high pressure washer, spraying it onto the deflector. As there was no air flow it was not quite as good as the above .

david

Edited February 18, 2014 by david 1220

[Gordon]

Also perhaps the caravan manufacturers should also use a wind tunnel to help wind resistance and drag when designing new caravans.

Some were doing it years ago . . .

[micktheshed]

I can only conclude that with the present aerodynamic shape of both car and caravans ( well most- theirs one make that has a profile of a brick ! )

You can't possibly be referring to the type I tow, or can you? LOL. I recon it is costing me between 5 & 10% more in fuel than any previous similar 'van of other, more (or any at all) streamlined, makes.

As regards the use of wind deflectors, there are just too many variables to allow any probable gains. Even if a specific unit was set-up under wind tunnel conditions the benefit would most likely only apply when heading direct into the wind. Side winds would destroy whatever benefit there was.

Having said that, I have found that the use of a streamlined luggage box does give noticeable improvements in fuel consumption. ....as long as it gets removed when the 'van does!