As long as the 10W-40 was a good quality oil, it is unlikely to cause any damage to the engine.
Audi actually recommends 5w-40, 5w-30 and 0w-40. So 10w-40 is not a huge change.
Many people like to use the thicker viscosity oil when the vehicle goes over certain mileage.
So just the oil viscosity shouldn't be any reason for concern.
Let me know of any questions.
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Tuesday, June 28th, 2022 AT 9:10 AM