Introduction to Audi A5 engine replacement: Understanding your options. When an Audi A5 engine fails, it’s not just a mechanical issue; it’s a significant decision point for the owner. The cost, performance, and reliability of replacement options play a pivotal role in determining the way forward. Engine replacement options range from reconditioned and used engines to rebuilt and remanufactured ones, each offering unique benefits and challenges. Whether you’re looking to restore your vehicle to its original performance or find a cost-effective solution, understanding these options is essential.