Originally Posted by Matt01
I think it's the particulate filter, it's cleaned out by heat and the engine deliberately running hot... It can increase the mpg by always running... Particularly if you're doing lots of short runs...
Yes this is undoubtedly what it is. I had the same issue with my A6 and thought there was something wrong with it. I called Audi on one occasion and the service department sent out a breakdown guy who, on arrival, told me that he had been called out to several Audi and BMW owners thinking their car was overheating. He was frustrated at the lack of understanding at the dealerships and even had an Audi booklet in his van which explained the particulate cleaning! Pity I didnít get one of these booklets when I bought the car!!