Regarding your Audi I suspect it is the same like my S6. When I did the testdrive I was quite shocked how laggish it was and there was no boost feeling. Once I changed from economy mode to normal or sports mode the car felt totally different and the MPG numbers have changed as well. And I guess the start/stop feature saves 1-2ltr/100km as well and I would not want to have one on the new Ford GT :thumbsdow
I know the Audi comparison was an apples/oranges comparison - well aware the NFGT must be much aggressive in the setup.
My Audi does not have start/stop (at least I haven´t found it ) and has been modified a bit to now making 475 hp .... not 28 mpg anymore but probably 22-23 in current trim (highway)
Ii´s going to be interesting to see the actual specs of the NFGT after such a long period of specilation & romours ..