What is the best way to keep the Ford Focus engine running smoothly?

I recently bought a used Ford Focus and I am concerned about the engine's longevity. What are some preventative maintenance tips I can follow to ensure my engine stays in top condition?

Regularly change the oil and filter, as recommended by Ford. This will keep the engine properly lubricated and clean any gunk that can cause damage.

Check and replace the air filter whenever it gets dirty. A clogged air filter can restrict air flow to the engine, leading to reduced performance and potential damage.

Don't ignore warning signs like strange noises or warning lights on your dashboard. These could be indicators of a bigger issue that needs to be addressed immediately.