The only thing intake boost in pressure provides is ability to burn more gas (at same RPM) thus more power. Power comes from fuel burnt not air injested. Fuel injection system maintains constant ratio of fuel to air (well ideally). So providing infinitesimally more (maybe) air to engine will be offset by small increase in power required to move vehicle forward from additional drag. More power needed = more fuel burnt = worse mpg (you can't fool physics).

Ingenuity of stock system is in fact that it uses that same/similar ram (which is composed of entire front clip of car) effect to pressurize area inside fender. Air/gas flows from area with high pressure to area with low pressure there is no such thing as direct or indirect flow <img src="/forums/images/graemlins/lol.gif" alt="" /> That why even if you turn you heater fan off air still flows into cab despite the fact the intake grill vents are almost horizontal etc.

I've studied gas/fluid dynamics for my mechanical engineer degree for two years. I can tell you aerodynamics and fluid flow is one of the most complicated subjects out there this side of quantum mechanics. I've not even began to understand acute details of it. So to definitely say this scoop at the roof provides more air to engine would be a far stretch of imagination.

I was planning to do simple test before I installed snork. Get sensitive vacuum gage and measure intake pressure before and after installation under similar load conditions. Of course time constrains didn't play in favor of this experiment. But for those with Safary you can do simple experiment never the less. Turn snork head facing backwards and see if you loose any power. (or better ask somebody to turn it for you and drive it without looking at it few times)<img src="/forums/images/graemlins/shame.gif" alt="" />
I did just the same due to the rain and no I didn't feel any noticeable decrease in power. And whatever gain is facing forward it will be offset by same loss facing backwards.
Someday I'll try a more scientific approach and use a gauge but it better be very sensitive one. <img src="/forums/images/graemlins/wink.gif" alt="" />