Type 57

Type 57 was a type of TARDIS used by Time Lords. It was more advanced than the Type 40 TARDIS, which was used by the Doctor. Experiencing a "slight hiccup" while flying the TARDIS to a point in Earth history in Tegan Jovanka's future, the Fifth Doctor commented that he "should have changed it for a Type 57 while [he] had the chance." (TV: Warriors of the Deep)