[aardvarcus]

I decided to put this in a new thread instead of burying it in my existing thread since I wanted to drum up some discussion and this topic isn't specific to my vehicle. Lets talk about wheel and tire fairings. To clarify, when I say fairing I am referring to structures fore and aft of the tire designed to prevent air from impacting the tire directly, not smooth wheel covers or wheel well covers. I know there are some disagreements on the exact name of such a device.

I have been doing some rough design on some wheel and tire fairings for my Tacoma. Not the little “air tabs” manufacturers are putting on vehicles, full on “deflect most all the air from hitting the face of the tire” fairings. My plan is to build rigid frames to hold conveyor belt material from the top into the desired fairing shape down below. This is not a new idea, like many things I have seen it suggested on this site before.

I have had trouble finding any good information on this subject (tire fairings in general), just picking up pieces here and there. Here is what I think I know. The air at the front under the car is flowing at an angle and not straight back (i.e. trying to flow out the sides), which the angle is probably around 30 degrees in the very front. This means the very front fairings need shaped more to the inside of the vehicle to deflect this angled air.

The air at the back of the front tires is still at an angle, but the angle is probably less now. I would think a boat tailed' type fairing would be appropriate here (with small curves on leading edges). I also thought the outside should be roughly straight back, and any boat tailing of this section should happen on the inside face, due to the angled air flow.

The air at the back wheels is probably more straight back, or at an angle low enough to not effect the design significantly. This leads to a more standard straight on semi-circular front fairing. I was thinking the back fairing should have the inside wall close to straight back, and the outside wall should have angling like a boat tail, so the exact opposite of the front fairing.

I have attached my very rough/preliminary designs to hopefully get some feedback. Note my sketches show drivers side details, passenger side would be mirror imaged.

I have been designing the front like a semi-circular curved leading edge, and the back like a mini-boat tail. Is this the correct way to design these items? Are their any established ratios or curves to use for wheel fairings? Any thoughts on minimum or maximum distances between the tire and the fairing? Any thoughts on sizes of the fairing in relation to tread widths and if any offsets are needed to the inside or outside?

Any yes, I know I really need a wind tunnel to actually know anything for sure about this. And yes that really isn't an option so I am really just looking for any helpful information anyone might have.