The early TFSI engines found in the A5, A4 and Q5 prior to 2012 have an inherent design fault which leads to high consumption of oil. The problem is caused by faulty piston rings, which allow small amounts of oil to leak into the cylinders, where it burns and therefore leads to high oil consumption. Over time this problem gets worse, and the range you can drive before needing to add oil decreases. In advanced cases there can be noticeable smoke from the exhaust under heavy acceleration, and it is also known to damage the actual cylinders themselves.