Is it beneficial to replace the stock air intake on a Ford Focus with a cold air intake?

I am considering upgrading my Ford Focus's air intake system to a cold air intake. I've heard that it can improve engine performance and fuel efficiency. Is it worth the investment?

In my experience, upgrading to a cold air intake on my Ford Focus significantly improved my engine's performance. It's a worthwhile investment if you care about getting better gas mileage and a more responsive engine.

I personally wouldn't recommend it. It may give a slight boost in performance, but the cost doesn't justify the minimal gains. Stick with the stock air intake for cost-effectiveness.