If you are looking for bling, ok, then it really doesn't matter just get the one that looks "cool"....but if you are looking for any mpg or hp gains, save your $......there is no gain to be had and you already have a factory CAI. Ok, let's just take a look at basic physics.....
The2013 Mustang 5.0 V8, for example if close to stock (assuming 6,800 max rpm& 90% volumetric efficiency- note that is race car spec and likely higherthan reality) can only suck in a maximum of 535 CFM, and the OEM flat panel filter ( 12.375” x 9.675”) will flow 718cfm, ....so how can just a CAI force more air into an engine thatis already injesting everything it can? It can't plan & simple- basic lawsof physics without a forced induction system.
What many view as an issue (is the plastic intake tube withits noise canceling design) actually increases air pressure. It is the samehydraulic concept used by fire fighters creating water supply where psi is low.By having the air cross the path at a 90 degree angle, the pressure isincreased proportionally. Fire fighters use what is called a “4-way valve” or“Blake Valve” at the hydrant where the water is cycled through the fire engine(pump) and sent back into the valve crossing the water flow at a 90 degreeangle. In this case it also acts as a sound canceling device! At low speeds,this can reduce the flow a tad (which is what most “feel”), but in terms ofpeak hp/tq, a good high flow filter is all that is needed....again, basicphysics.
Now about this new marketing hype that if you have a CAI youneed a custom program………….hogwash!!!!!! The OEM software system is designed to adjust the fuel mixture up to 10%(25% on the 2000+ mod engines).......that’s more than enough to handle fuelmixture adjustments up to 7,000 foot elevation change! (for high elevations 8,000+ there are oemsoftware programs for those specific applications)….the reason for the "software programming" is becsue of "Bad Engineering" on the part of the aftermarket CAI manufacturer......as that had moved (needlessly) the intake sensor location, and it is much cheaper to mfg a 'pipe" straight than it is to create an aerodynamically designed offset ...plus, the retailer then gets to sell you are software programmer- everybody makes $ on a product that produces No repeatable, scientifically verified performance (as far as a stock or near stock engine goes).
In 2012 on jay Leno’s garage, (showing off the new 2013 Mustang GT) when inquired, Fords Mustang Chief Engineer DavePericak
specifically stated that the use of an aftermarket CAI will donothing to gain any power. http://www.youtube.com/watch?v=4LXYK4rR7Sw
IMHO, save your $ to put it towards a real use!!!!!