How do I properly maintain my Nissan Patrol's engine performance?

I've noticed a decline in my Nissan Patrol's engine performance and I'm not sure how to fix it. Any tips or advice on how to properly maintain the engine?

Regularly change your engine oil and oil filter to keep your engine running smoothly. Make sure to use the recommended type of oil for your Nissan Patrol.

Check your air filter and replace it if it's dirty. A clogged air filter can decrease your engine's performance.