I'd be very curious to see if the fuel consumption can in any way be reduced with the remap (even by a very small margin) ... what pjr wrote, regarding the cold start, the FSI engine takes some 10-15 seconds working on 1200 RPM when cold, before dropping to normal 650-700 RPMs ... if the ECU remap can at least impact this somehow, then why the hell not, it will already be worth the trouble ... if I was that worried about actual fuel economy, I wouldn't obtain a 260 HP car, right? This is more of an exploration of what can be achieved ... was also thinking about throttle pedals and such, this is much cheaper and unobtrusive in a physical sense
It can't be done end of.
Cat heating you can switch off, set minimum elevation factor to 4, done.