McDave wrote:So, it would seem that the "gap" between the TV and Trailer is responsible for about 25% of the drag of the combo. No surprise really. with both high and low pressure, trailing and leading faces and different body width/height. This being the case, possibly this is the area that would yield the most mileage gain. Also no surprise, this would be the most complicated because of the articulation and vehicle differences. Here is an ingenious solution for big rigs that could be possibly scaled to our trailers.
http://www.donbur.co.uk/gb-en/docs/1503 ... ochure.pdf
Put on your thinking caps and have some cold barley thinking fluid and lets see how do-able this could be. For pickups lets assume there is a topper, or a van as the tow vehicle.
McDave
I found a few cases where a owner sold a smaller TT and bought a longer heavier fiver and got the same fuel mileage.. So that adds to the theory that smaller "gaps" are responsible for better mpg..