Крис Младенов 4.0 TFSI V8 Common Problems: Turbos and Servicing The 4.0 TFSI V8 is the heart of the RS6, RS7, S6, S7 and S8. Two turbos, enormous torque and an engine note you won't forget in a hurry. What an engine! But there's something I want you to understand ... 4.0 TFSI RS6 S8 Turbocharger V8 Oct 26, 2023