How to maintain fuel efficiency in a Toyota Land Cruiser?

I recently purchased a Toyota Land Cruiser and I've noticed that its fuel efficiency has started to decrease. What steps can I take to maintain its fuel efficiency and optimize its performance?

Regularly check and replace air filters and spark plugs to ensure the engine is running smoothly and efficiently.

Avoid aggressive driving and maintain a consistent speed to reduce fuel consumption.

Make sure your tires are properly inflated to improve gas mileage.

Consider using a fuel additive or higher octane gasoline to improve engine performance and fuel efficiency.