Why is my Kia Sportage experiencing poor gas mileage?

I've noticed that my Kia Sportage's gas mileage isn't as good as it used to be. What could be causing this issue?

One possible reason for poor gas mileage could be a dirty air filter. Make sure to regularly check and change your air filter to improve fuel efficiency.

Another potential cause could be underinflated tires. Make sure to regularly check your tire pressure and maintain the proper levels to improve gas mileage.

It could also be due to a faulty oxygen sensor. If this is the case, it's important to get it replaced as it can greatly affect your fuel economy.