Why is the MPG on my Ford Focus decreasing?

I've noticed that my Ford Focus' fuel efficiency has been decreasing lately. Is there anything I can do to improve it?

One possible reason for the decrease in MPG could be due to a dirty air filter. Check and replace it if necessary.

Another factor to consider is tire pressure. Make sure your tires are properly inflated to improve fuel efficiency.

You may also want to get your fuel injectors and spark plugs checked as they can affect engine performance and gas mileage.