Why is my Kia Niro's MPG decreasing?

I've noticed that my Kia Niro's MPG has been decreasing over the past few months. What could be causing this and what steps can I take to improve my fuel efficiency?

Make sure you are regularly maintaining your Kia Niro, including getting regular oil changes and tire rotations. This can greatly improve your fuel efficiency.

Check your tire pressure and make sure it is at the recommended level. Under-inflated tires can cause a decrease in MPG.

Avoid aggressive driving and excessive idling, as these can negatively impact your MPG.