Roof top fairings?

[cruisinTx]

I have yet still another newbie question. While we were having lunch in Amarillo yesterday a 5th wheel rig drove by with a roof top fairing on the tow vehicle. That piqued my interest as I had not yet seen this since I started considering a fiver. I may have seen them in the distant past but now that I am actively trying to learn more about them, I am more observant of the details. I don't see any pictures on the various FB pages or web sites I visit where a tow vehicle has a fairing. After getting home, I began to research that a little. It took a while to find the proper terminology. I did find one pretty well written article about them that was very informative. I figure asking those of you here with real life experience might yield some good info. I'd prefer responses from those who have actually tried them, not those who oppose them without any first-hand knowledge but dislike them just because someone else told them so.

The questions are: do they work? if they work, what styles/brands are best? if they work, why aren't there more in use? I'm sure there are more questions but I'm too new to know what they are. 1000s of 18-wheelers use roof top fairings for a reason so is it just not practical with a fiver because of not being able to get the fairing close enough to the nose of the trailer? Dunno, y'all enlighten me.

[huntr70]

Had one. It did raise the bug line on the nose of the 5th wheel, but did not change mileage at all.

I don't think you can get them to push the air high enough to actually get over the front.

[vonzoog]

They were more popular years ago. Not sure if they really help fuel economy. Years back the 5th wheels had blunt flat fronts on them. Today most 5th wheel have fiberglass/plastic formed shaped fronts. My guess is the newer 5th wheels are as good (or not) for fuel economy as the old truck fairing did.

[Bungy]

I have yet still another newbie question. While we were having lunch in Amarillo yesterday a 5th wheel rig drove by with a roof top fairing on the tow vehicle. That piqued my interest as I had not yet seen this since I started considering a fiver. I may have seen them in the distant past but now that I am actively trying to learn more about them, I am more observant of the details. I don't see any pictures on the various FB pages or web sites I visit where a tow vehicle has a fairing. After getting home, I began to research that a little. It took a while to find the proper terminology. I did find one pretty well written article about them that was very informative. I figure asking those of you here with real life experience might yield some good info. I'd prefer responses from those who have actually tried them, not those who oppose them without any first-hand knowledge but dislike them just because someone else told them so.

The questions are: do they work? if they work, what styles/brands are best? if they work, why aren't there more in use? I'm sure there are more questions but I'm too new to know what they are. 1000s of 18-wheelers use roof top fairings for a reason so is it just not practical with a fiver because of not being able to get the fairing close enough to the nose of the trailer? Dunno, y'all enlighten me.

They were popular years ago with the flat front rv’s, that’s why truckers use them. I don’t think they’d be beneficial with today’s more aerodynamic front caps.