http://www.aptuned.com/blog/cold-air-intake-vs-short-ram-intake-whats-the-difference.html
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What is the difference between a cold air intake and a short ram intake?
As the name implies, a short ram intake is "short". Due to it's size, the intake pipe doesn't stretch far away from the intake manifold, so the air filter remains somewhere near the engine. A cold air intake has longer piping, and is designed to push the air filter away from the engine into an area that has colder air, hence the name cold air intake. Typically, since the cold air intake draws in cooler air it usually makes more horsepower than a short ram. However, depending on engine design, this isn't always the case, and we'll explain further below. A short ram intake is generally less expensive as well, and easier to install and service since the air filter is typically easy to see when you pop the hood. A cold air intake is longer, and places the air filter farther away, sometimes in a fender, so installation is more difficult as is service, and is usually more expensive."
It is really dependent on the car as well as what is available. Not all cars have the same makers. For EVOs, it's Amsoil or Perrin. No need for a CAI as the location and function of the body parts determine if enough cold air can be obtained.
Remember more horsies from colder air temps!