Take a gallon jug and fill it one third of the way with water so that if it is held on it's side nothing would come out . Now drive down the road and hold it out the window , you will find if held in the upright position the water will be sucked out but if you put it on it's side with the opening to the rear it will not . Our if you own a vacuum gage take a hose and with one end hooked to the gage hold the other end out the window while driving and see what happens when you hold it up our lay it on it's side .

 

Yep!

we sold a 95 dodge diesl to a guy, (he died shortly after it)

but when he bought the truck, he said: Cummins is a great engine,

but i had to replace a turbo, cuz of the blowing wind makin it wind for a longer time! he didnt have covered it!

(and all the farm equipment we buy from the usa, comes with duct taped exhausts!)