Q: Would a cold-air intake benefit my car?

Hi there. You might be better served to contact a Mazda shop locally to seek their advice after they inspect your car. The problem with cold air intakes and aftermarket intake systems and that they often negatively impact the sensors, especially those that monitor fuel and emissions systems. Unless the ECU is updated to increase ignition timing to match the increase in air intake, the car will run worse believe it or not. Another good source of information would be talking to a professional air intake company customer service rep - like K & N filters for example. They are really helpful.

When trying to adjusting the engine to accept more air, then you would need to change internal parts. By putting on a aftermarket air filter that is a cone type cold air intake system, the engine will be able to run quicker when throttling hard, but loose efficiency when driving in traffic at low speeds due to sucking in all the engine temperature heat under the hood. I recommend keeping the factory intake or plumbing the cone type cold air intake outside the engine compartment. Be care not to put the filter below the engine level as when driving in wet conditions will draw water into the engine. If you need further assistance with your air intake system, then seek out a professional, such as one from Your Mechanic, to help you.