[hilifta]

This is a subject that has had me very curious for quite a while. It was while looking at 2 photos this morning that I took yesterday, that has finally made me put pen to paper.
Firstly look at Blair's International with it's air deflector covering the whole of the front of the curtainside, then look at the air deflector on the Semco Mack. It looks a real half arsed effort and only covers about half of the front of the curtainside and surely it can't be anywhere near as effective as the one on the Inter.

Now, I am not an expert by any means on this subject, but here are a couple more observations.

Out here it is very common for trucks to have mud flaps not only behind the wheels but all the way across the rear of the vehicle. Now surely this hinders the flow of air escaping from under the vehicle and causes drag, which in turn must increase fuel consumption.
I also notice when in a straddle, high up, that many of the bulk grain trucks do not put their covers back on when empty. Again with all the air swirling around the trays, this again must increase drag.

Now to container trucks, I know there is not a lot you can do to eliminate the gap between the cab and a 20ft box, but surely in this state it is better to have no deflector at all, especially the big high ones as fitted to some trucks.
Having a big high deflector must increase the dirty air swirling around between the deflector and container.

One more thing, does having skirts down the side of truck improve the aerodymanics. If it does, why do so few trucks have them fitted.

And finally, why oh why do you have all those lights up on the roof, as I see on UK trucks. They must play hell with air flow.

I get the feeling that very little intelligent thought is going into this area, which is very surprising due the large cost component that fuel represents.

What are your thoughts, or is it me that's way off beam here.

Mike