Circumnavigation on Kerbin-Rescaled to 2.5

The FAT-455 is also the reason I ended up using the gas guzzler Rapier instead of the sensibly more fuel efficient Whiplash - I need to reach higher altitudes in order to keep the FAT-455 wing cool at the desired cruising speed. Curiously, while testing both engines I ended up realising that the total fuel cost for the journey would be almost the same for both engines: the ideal cruising altitude and speed for each engine has approximately the same fuel consumption : between .57 and .67 units per second - the extra speed the Rapier gives ends up counter-acting its fuel consumption.