my a6 130 awx seems to take longer to warm up than my old passat 130 tdi and seems to use more fuel at start up too.

the needle stays in cold position for around 3 miles or so and then once it starts moving gets to the middle quite quickly..

The fuel gauge moves over the first few miles of driving which is something that never happened on my passat..

I have noticed that the upgraded coolent temp sensor has been fitted, could it be a faulty themostat..

Thanks to anybody who can help.