Thanks very much for that. I did try the Met office web site, but could not work out how to navigate to the info I wanted. Tried the search facility with no luck etc.Cheap 'n' Cheerful.
Historic Met office data shows for Bedford 9 knots from the West for 8.00 Summer Time on both the days you mention.
Tim
Thank you very much for that. I am sure that one reason why I achieved such an improvement is that the aerodynamics of my van are really rather poor as they are, compared to the modern ones you describe. It is quite likely that the car/van combination I had was one that stood to benifit the most. Others may not be anywhere near as successful.Back in the mid 80's I was a student at Loughborough University studying Automotive Engineering. With me on my course was a son of either a director or senior manager at Swift, (I can't remember exactly). On one of our aerodynamics projects the two of us wind tunnel tested car caravan combinations to assess what features helped reduce drag and therefore fuel consumption. I can't remember the figures anymore but apart from some fairly impractical ideas I rememebr that the following improved drag.
On the caravan sloping the front windows back with as generous a transition as possible from front to roof. That made the biggest difference of anything we tried. A sharp cut off at the back of the roof with no radius. Blending the front in to the sides of the caravan as much as possible.
I have no idea whether our findings were fed back in to Swift but their caravans are pretty good compromise over the shape we came up with and a practical caravan.
Regarding the car, we obtained slightly better results with an estate car than traditional 3 box saloon. We also tried wind deflectors but in all the tests we did, we found they increased drag rather than reduced it. We were working with scale models and the real world is not always the same. I know one company is showing good results with a delfector tested at MIRA. MIRA are a very reputable orgainsation and I am sure their results are accurate but it would be interesting to see the full results, test conditions, speeds tested etc.
This is a follow up to an earlier posting, I've just returned from 3 weeks caravaning. On the long motorway runs the Aeroplus made the unit so much more stable, no wobbles when white vans race past, it was a pleasure to drive, still keeps the bugs off the van. Bad news as near as i could tell mpg increased by 1mpg with the Aerofoil fitted, I stopped at services and removed or refitted it to make sure.THANKS FOR THIS
LET ME KNOW HOW YOU GET ON WITH YOUR AEROPLUS AS THAT IS THE ONE I SAW ON EBAY!