Alright everyone. 

I have a 1.8T, petrol, A6 from 2000. Drives nice, sound car but...I believe the turbo is dead. When in 4th, there's pull, im doing 50mph and 2500 revs - I go into 5th and I'm on 2000 revs at 50mph. 

Surely that isn't normal for a 1.8T? 

I bought a code reader, see if a sensor or anything would show....no codes, nothing. So now I'm stuck, a recon 1 is £500, then there would be calibration....the car cost me 450, I do like it but I do some long hauls on the motorway so climbing up to 70mph is easy because the car can pull, but I'm then doing, in 5th gear at 70mph....almost 4000 revs. 

Any advice is massively appreciated. 

That does sound a bit high, sure the clutch isn't slipping?