Z car aerodynamic enhancements for tomorrow

[Sideways]

Now that I think about it the wind tunnel in question only blows at 80 mph and then extrapolates up to whatever speed you think you'll be going. Maybe it would show if the air actually went 140 or 150...

 

Maybe its just mumbo jumbo but ive seen a small handfull of tests thatve showed cars to get 1-3mpg on average over a few tanks of gas with a cleaned and waxed body. But people will say anything to sell you something

[Michael]

It's important to note the difference between large accumulations of obstructions (mud, ice) and just dust-type covering on painted surfaces.

 

For airplanes wings relying on natural laminar flow for drag reduction, even small surface contamination such as dust and dead insects can make a significant different in performance. This also happens in wind tunnel test, for example when grime dislodges from the screens in the settling chamber and makes its way onto the test article; one observes higher drag on the test article than predicted in "clean" flow. But I would be highly surprised if a similar thing happens to any but the most exotic and highly-optimized cars.

[capt_furious]

Many fighter aircraft squadrons operating in the European theater during WWII (particularly, the 61st FS of the 56th FG, and more specifically, Francis S. Gabreski's aircraft for an individual example) made a practice of applying heavy coatings of wax to their aircraft in order to give a small critical level of improved fuel consumption and ability to hit VNE more quickly. This practice carried over from lessons learned in air racing in the 1930s. Air racers at Reno today treat their aircraft in the same manner, they are fastidiously clean and the skins of the aircraft are slick as humanly possible.

 

When you're dealing with triple digits and even subsonic speeds, you bet it's beneficial to keep surfaces clean...for motor vehicles, it's probably more effective to tape off panel seams and smooth transitions between body angles and pieces, but every little bit helps, and it's generally good practice to keep your car clean regardless.

 

...you'd be amazed at how much dirt and trapped debris / chemicals contribute to corrosion. One of my AF briefings this past week even made a point about using grease pencils to mark aircraft instead of a pencil because the pencil's graphite acts as an anode.