Hi all. Just joined today. Not had an Audi since a couple of 80s in the 80s. Saabs since. I've just bought a 2013 a3 2.0 tdi sportback sport with 80k on it. Fsh. and as I didn't know what to expect it was ok. Not as responsive or torque as my Saab 2004 .Anyway I realised an hour after buying and driving home that the heater didn't work so the garage have taken it back in and given me a courtesy car. Exactly the same model same mileage , 2014 instead of 13 but 6 months apart. The difference in power is night and day. The one I bought is okay I thought but the courtesy car is more like what I was expecting. 50% of a difference I'd say. Could the non working heater cause a power loss? The reservoir isn't losing coolant. T.I.A.