What is the difference between the 3 different sizes if Injen intakes besides the cost? Advantage and disadvantages? 8) Please explain.

Short intakes benefit high reving engines while long intakes benefit lower reving engines.

it's a physics principle, there are a few web sites that explain it in detail . I was building an individual throttle body set up for my type R powered CRX and I ran a crross a web site that would calculate the harmonics and % of air flow increase over a certain RPM range.

So for a standard xB you would want cold air not short ram correct?

I drive the majority of the time on the freeway, so I went with a short ram. The Matrix is used for both so it has a cold air intake. You really can't go wrong w/ either INjen intake.