No you can't, because they were no good, for a wind deflector to work there needs to be only a very small gap between it & trailer, ie like on the roof of an artic truck cab, so no point of putting one on a car roof when towing a caravan.
As well is two words!
How does a sage know everything about everything? or does he? or does he just think he does?
Remember, if you buy something you bought it, not brought it.
To be effective a deflector needs to direct air around sides & top of of trailer & that one does not even come close, the gap between it & caravan is far too much & caravan being wider than car renders it even less effective, there is just as much turbulence at side of car/caravan than over top, they obviously haven't thought of that?
It costs £100 + you need add cost of roof bar to fit it to. I'm sure the makers will claim it is an improvement over the Windslammer from yrs ago so taking a positive view of this device, maybe it will pay for itself after 15yrs of towing?
As well is two words!
How does a sage know everything about everything? or does he? or does he just think he does?
Remember, if you buy something you bought it, not brought it.
This bit made me smile..'It has also been proven to achieve a 15% fuel saving in controlled tests'. If you read the Australian writeup, it was conducted along 1500miles of the Stuart Highway, this will be an almost empty road that runs up the centre of Oz, so if your UK caravanning consists only of driving along the M6 at 2am then perhaps you could achieve a similar saving?
We had good results with a Dutch wind deflector on our old 1980's Vauxhall Astra Mk1 Estate 1.3. Without the deflector it would struggle to hold speed on motorways, but with the deflector is was much easier to drive.
Possibly more effective in an estate car with a longer roof, plus they need to be located as far back on the roof as possible, the instructions were very specific about that.
We had a Sprite Alpine at the time.
We've still got it and are going to try it out on the Discovery with the bix 6-wheel trailer behind.
My dad used to have a wind deflector years ago n suggested it might help with the fuel consumption when towing my liddle box on wheels..we not had it for long, but towed it back from Newcastle to Blackburn, when we went to pick her up we went up with a full tank n hardly used a quarter...on way back we had a nearly empty tank...
------------- 1st outing...Blackpool caravan club site (april 2014)
As pointed out, if there is any benefit it will be at 60mph on a clear motorway, at slower speeds there will be no saving & even at motorway speeds with buffeting from other vehicles on a busy rd you will gain nothing. Unless you could put deflectors around sides of car as well & close to caravan I'm failing to see any savings. The hills on the route you describe would have increased your towing fuel consumption by a large factor & a deflector would not have really helped uphill at slower speeds.
the sun roof on my mondeo estate is the type that tilts open at the back then when fully open stays tilted but slides back above the roof of the car if you know what I mean.
A few years ago on a hot day on the M6 going to the lakes with the roof fully open I discovered by accident that I get 3 - 4 mpg more towing with my sunroof open according to my trip computer. Have tried it a few times since and it does make a difference.
Only any good if its not raining though..
i have a roof box mounted as far back on roof as i can. it makes for a more stable tow, sometimes it empty sometimes its full with awning ground sheet.its a halfords 360litre square box.