What do you know about cold air intake system in terms of acceleration, top speed, horse power, gas mileage, price, and practicality.F.Y.I. I have a 2003 Ford Focus SVT Hatchback
The HP gain is mostly seat of the pants, the car will feel faster because it will rev quicker and give you the feeling of a gain in HP, when you only gain maybe 2 - 4, without actually dynoing before and after there is no way to know for sure how much gain you get despite what it says on the box, but it sure makes the engine sound cool. Without the addition of say, headers and and a freer flowing exhaust a CAI is more mind over matter
As I read it your question is about noise. In California it is illegal to change your exhaust to make more noise. It has been this way for at least 40 years (since I took drivers ed). Is the law enforced? In some communities and at that selectively.
its illegal to have a loudness level past 93db (could be 94). so make sure the aftermarket exhausts arent. most of them are generally around 100-110 db however.
I own a 2008 SES Focus and my model comes with a cold air intake system and lifetime air cleaner. The 2.0 engine in my Focus runs like a race car! I raced a kid in his so called FAST HONDA and left him sitting at the stop light with his mouth hanging open! So much for those overpriced rice burners!. My Focus gets 38-40MPG. I guess the tail pipe end on the Honda might be bigger But the 2008 Focus leaves those rice burners wishing they had a Focus too! The cold air intake works great on a Focus I recommend it! and whatever anyone does DONT spend your hard earned money on a junk JAP car! Buy American! 2008 Ford Focus! 140HP!
a cold air intake will not have a great effect on so many of the areas in your question. the colder the air the more dense it is, that tied into the increased amount of fuel that the computer will feed into the engine makes more power, giving you an increased power and acceleration, but the top speed is still limited by a few factors such as the gear ratios and the engines rpm range. this is sometimes limited by a governer. the fuel economy will be little bit worse due to the increased amount delivered to the engine.
