There's a certain amount of standard advice for shooting night photography. One of them is to shoot either Fujichrome 64T or Kodak Ektachrome 160T for film. Both films are well-behaved and well-characterized tungsten balanced slide film. With slide film, you don't need to worry about automatic machine corrections like you do with print films, so that's easy to understand. Both films have about as reasonable figures for long-exposure reciprocity as you'll find in a manufacturer datasheet.
But, tungsten color balance? Why do most night photographers shoot using tungsten color balanced film, or the tungsten setting on their digital SLRs?