The long-held notion that you should let your car idle in the cold is only true for carbureted engines. But you still might need to wait a while before driving off in subzero temps.
Read the full article at …… https://www.popularmechanics.com/cars/car-technology/a19086/warming-up-your-car-in-the-cold-just-harms-engine/
MG ZT info mods and maintenance 