Freezing weather and auxiliary power units

[mgcm]

With the freezing weather upon us, does anyone know the latest improvements to engine performance to deal with sub zero -10 conditions? I was thinking in terms of auxiliary power units.

 

[londonmidland]

Speaking of cold weather, does it affect the way the engine/train sounds in any way?
I was on a Meridian the other day and it sounded ‘different’

Hard to explain but if you skip to 16:10 you’ll hear it. It’s sort of like an inconsistent whine sound.