Question on Diffuser
 

I had a question about the Diffuser Pro.

How come i see some with the extra wings on the sides. Is that an option or are they 2 different diffusers? what are those called?

The extra loop-things on the sides are part of the "vortex/bowtech generator" package, along with 2 extra vertical fins in the center (below lic. plate). It's an add-on to the standard Pro model
http://www.jt-imports.com/Bowtech%20generator.jpg

rotor rooter nailed it, but i question if it actually does anything. you really need a full underbody diffuser like on an Enzo

Well anything will help cause less turbulance, compared to the plastic piece that sits at a 20-30 degree angle against the flow of air...
That will translate into some performance gain.... how much is questionable....

I spent some time yesterday in a windtunnel, in San Diego, and stupid shit, like a bycycleist, @ 20-30 Mph. does something like tuck their head in a differnet way that they're not used to, can shave off 200+ grams of wind resistance, causing him to shave off .5 - 1 second per mile... and @ 5-10 miles you do the math... and that's @ 30mph...

Anything that reduces turbulance will help, wether or not you'll be able to feel the difference, even in gas milage is doubtfull unless you always drive the same way .... not likely....

-DC

The extra pieces create a vortex from the side of the diffuser which separates the air flow above/side of the car from the underbody air flow, stopping high pressure air flowing to the (hopfully) low pressure underbody air and lowering the downforce.

...or thats why aircraft recently all run winglets. on a road car the difference is probably very slight, but as my mother once said "it all adds up"