These devices are eye candy only. Just a way to get you to buy a fancy air filter that you don't really need. So get one that you think is the most pretty. It's not as though you are feeding a big block V8 with a big Holley carburetor. So how much airflow do you really need? In addition, believe it or not, the factory engineers designed your stock air intake including the stock air filter to supply the engine with more than enough air. If the factory engineers wanted to restrict airflow for some strange reason, they would have simply installed a smaller throttle body. The air filter used in the cold air intake is the only component that may give you any real improvement. In general these air filters will flow a little more air than the stock paper disposable element, but only if they are routinely cleaned and oiled. If they are allowed to get dirty, they will work no better than the stock paper air filter. However, with a late model fuel injected engine, avoid the ones that use the washable oiled gauze elements. If even the slightest amount of oil from the filter gets on your Mass Airflow Sensor, it will foul the sensor. This sensor is located in the tube between the throttle body and the air filter housing. If fouled, it will send erratic signals to the engine management computer. This will mess up your fuel / air mixture to the point that you could have even less power than you had before you added this component. If you already have one of these types of oiled air filter elements, you should clean the Mass Airflow Sensor with the correct cleaner every few months. Use Mass Airflow Sensor cleaner, and not carburetor cleaner, or you will destroy the sensor. Instead of the cold air intake, I would just simply add a low restriction air filter element. Personally, I hate washing and oiling air filters. A messy job. I would stay with the disposable paper air filter for this reason.
The best cold air intake is the one that came on the car when it was new. NO aftermarket CAI, is going to produce extra HP and they all will cause you to get worse MPG. But they might sound oh so cool, they all do nothing at all.
