How are they different and which one is best for performance?
CAI takes in air outside the engine compartment forward, or to the side of the radiator. RAI takes in air outside the engine compartment above the hood, and slightly increases the air pressure into the engine. Looks cool too. If done properly.
only if the car is considered a commercial vehicle all eighteen wheelers have them by a federal law. and are checked on a regular basis
I don't have one, but my parents do after they had a car fire. I don't think they're required but are a good idea.
Ram Air typically doesn't do anything better than a Cold Air intake until you are well above 90 mph. Typically, on a street vehicle, you will seldom see any real effect from Ram Air.
Cold air intake will increase your performance a little, depending on style and manufacturer. Ram air is forced air, this will increase performance much more than the cold air intake, it pushes more air in to the engine.more air in better performance. Do your exaust as wella better exaust will work well with the intake system. The more air in and more air out principlea cheap way to enhance performance.
