While a dirty air filter alone may not directly cause an MOT failure, it can lead to increased emissions or engine performance issues that could result in a fail. Keeping your air filter clean helps ensure your vehicle meets environmental and performance standards.

No — the engine air filter cleans the air going into your engine, while the cabin air filter filters the air entering your vehicle’s interior through the ventilation system. Both are important and should be replaced regularly, but they serve different purposes.

In many vehicles, replacing the air filter is a simple DIY task that takes only a few minutes. However, some cars have more complex setups. If you’re unsure or prefer a professional touch, our mobile mechanics at BookMechanic.uk can do it for you on-site.

A clogged air filter restricts airflow to the engine, which can lead to poor performance, reduced fuel efficiency, increased emissions, and even engine damage over time. Regular replacement is a low-cost way to prevent more expensive repairs.

Most manufacturers recommend changing the air filter every 8,000 to 15,000 miles or once a year, but this can vary depending on your driving habits and environment. Driving in dusty or high-traffic areas may require more frequent changes.

Common signs include reduced fuel efficiency, sluggish engine performance, unusual engine noises, a dirty or discoloured filter, or the check engine light coming on. If you’re unsure, a mechanic can inspect it during a routine service.