[77newell]

If your radiator shroud is the same as on the 93 coach I had, it is very inefficient. It is designed for suckling air through the radiator rather than blowing it through as occurs in our use. If you look online for images of rear radiator rv pusher chassis you will see a bell shaped inlet to the fan and the fan blades are entirely within the shroud, our coaches have neither of these features. I taped yarn strips onto the shroud just back from the fan far enough not to get ripped off. With the engine running there was lots of turbulence shown by the yarn and much of it was flowing outwards, not inwards, indicating that air at the tips of the unshrouded parts of the blades was being thrown outwards before circling around and hopefully being captured by a part of the fan that would force it through the radiator. I don't know the percentage of loss this represents but with our units every loss can make a difference.