What is the best way to improve the performance of my Ford Focus engine?

I've been noticing a decrease in power and acceleration with my Ford Focus engine. What can I do to improve its performance?

First, make sure to regularly change the engine oil and filter. This will keep the engine running smoothly and prevent any future issues.

You can also consider installing a performance air filter or upgrading to a high-performance exhaust system. These modifications can increase the air flow and improve engine performance.