Fuel
According to the Thirteenth Doctor, positrons produced by the Tsuranga's particle accelerator interacted with the fuel materials to produce heat, which produced thrust. (TV: The Tsuranga Conundrum [+]Loading...["The Tsuranga Conundrum (TV story)"])
The Rocket ZA685 operated on a chemical fuel, of which there was barely enough for a return journey from Earth to the Moon, however the Moon continued to have fuel storage into the 2080s. (TV: The Seeds of Death [+]Loading...["The Seeds of Death (TV story)"])
TARDIS engines made use of fuel rods that had to constantly be submerged within the TARDIS' liquid fuel lest they start to warp. (TV: Journey to the Centre of the TARDIS [+]Loading...["Journey to the Centre of the TARDIS (TV story)"])
In the Battle of Floor 0507, Nardole devised a way to remotely detonate the fuel rods beneath the holographic floor, allowing the Mondasians to trick the Cybermen into thinking they had powerful weaponry. When surrounded by Cybermen, the Twelfth Doctor detonated all of the fuel rods on the floor. (TV: The Doctor Falls [+]Loading...["The Doctor Falls (TV story)"])