How to diagnose and fix the lack of acceleration in an Audi 80?

I am experiencing a lack of acceleration in my Audi 80, particularly when trying to speed up on highways. It feels like the car is struggling to catch up and the engine is making a high-pitched noise. What could be causing this issue and how can I fix it?

It is possible that the spark plugs or ignition coils in your car are worn out, which can cause a lack of acceleration. It would be best to have these components checked and replaced if necessary to improve your car's performance.

Another possibility is a clogged fuel filter, which can restrict the flow of fuel to the engine and cause a lack of acceleration. Consider having your fuel filter replaced to see if it resolves the issue.