How do I improve the performance of my Audi engine?

I've noticed that my Audi's engine has been running slower lately. What can I do to improve its performance and get it back to its usual speed?

First, you should make sure your engine oil is clean and at the proper level. Dirty or low oil can cause engine sludge buildup and decrease performance. Also, check your air filters and replace them if necessary.

You may also want to consider using a fuel additive to clean out any deposits in your fuel system. This can improve your engine's efficiency and increase its power.