How much if any improvement in gas mileage do the fairings or wings on top of the pickup cab provide?
Our website covers this in our aerodynamic roll down tests used in product development. It was found that the adding on spoiler “wings” for a pickup cab can reduce the aerodynamic drag by about 1 1/2% as long as it is hooked to the 5th wheel. Now that is fine except they increase net drag on just the truck alone when it is driving around without the 5th wheel and that is (for most 5th wheelers) about 90% of the total miles on the tow vehicle. So, unless you are a commercial driver and most of your miles are hooked up and towing, the expense seems to be high and the net average gain almost non-existent.
The amount of drag it can reduce depends from bike to bike and their respective aspect ratio. The better the quality of motorcycle fairings,smoother is the airflow around the surface and better the performance.
