I'm in the market to purchase an A4 1.9 TDI (Probably an SE or Sport 130PS version maybe a Quattro).

I'm really after getting the most MPG out of the car, are there any companies that do remaps that increase the fuel economy (Fuel economy is my main objective as long as I do not loose performance). If I gain performance as well then that would be great. A friend told me that you can get 3 types of remaps for Audi's:

1. Lots of MPG improvements but only slight performance improvements
2. Lots of performance improvements but slight MPG improvements
3. A balance which sees a small improvement to both

Obviously MPG depends on how it is driven. However, I'm talking about driving it with a medium weighted foot.

Also, are there any one click boxes that allow toggling between a remap and a standard map? I'm after this so there is no visible signs of a remap at all. Thanks in advance