Post by The DoctorWhy? Black holes are the source of fuel.
Yads lies again.
The Time Vortex powers the TARDIS. The Doctor said so in Parting of the
Ways.
The Matrix powers the TARDIS. The Doctor said so in the Doctor's Wife.
The Eye of Harmony powers the TARDIS. The Doctor said so in Journey to the
Centre of the TARDIS.
A replica of the Eye of Harmony powers the TARDIS.
Artron energy powers the TARDIS.
Artron energy radiated from the prime Eye of Harmony on Gallifrey powers the
TARDIS.
Power from the Rift in Cardiff powers the TARDIS. The Doctor said so in
Utopia.
Artron energy powers the TARDIS.
A constantly collapsing star powers the TARDIS.