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.

It's not the heater failure causing the power loss. It's something more fundamentally wrong with your car. Can you exchange it for the better car?

I thought about that but it's the after sales guys company car.

Make them aware you're concerned that the two cars are totally different despite being mechanically the same and ask for a refund? You're allowed a refund up to the first 30 days after sale. 

3 hours ago, Billy88 said:

I thought about that but it's the after sales guys company car.

In other words he can afford to thrash it because he did not pay for it.

No, it's thr other way round.