On Jan 19, 9:04*pm, Dave wrote:
I have just been watching them and a thought crossed my mind.
How do they stop the diesel from going solid in the tanks and pipes?

Recirculating pumps.

Most (all?) petrol FI cars circulate fuel continually between the
engine and tank, the same approach is used in big trucks with heaters
so basically if it is running it stays running (they do not shut off
big construction kit in the coldest parts of the world and big trucks
are no different).