Why does my Audi A3's engine feel inefficient after long drives?

I have noticed that after driving my Audi A3 for several hours, the engine starts to feel sluggish and less responsive. Is this a common issue with Audi A3 vehicles? What could be causing this and what can I do to improve the engine's efficiency?

One possible reason for the decrease in engine efficiency could be the build-up of carbon and dirt in your engine's combustion chambers. This can lead to hindered fuel flow and decreased power output. To prevent this, make sure to regularly schedule engine cleanings and use high-quality fuel.