Here are some ways to find this information:
* Consult the owner's manual: This will provide details about the engine specifications for your exact model.
* Check online sources: Websites like Edmunds, Kelley Blue Book, or Autotrader usually have detailed information about car models, including engine horsepower.
* Contact an Audi dealer: They will have access to the most accurate information about the 2009 A3 models.
Please note that the horsepower can vary depending on the specific engine configuration (e.g., gasoline vs. diesel, displacement) and transmission type.