We show how to construct consistent truncations of 10-/11-dimensional supergravity 3-dimensional gauged supergravity, preserving various amounts supersymmetry. show, that as in higher dimensions, can be defined terms generalised $G$-structures Exceptional Field Theory, with $G \subset E_{8(8)}$ for the case. Differently from Lie derivative $E_{8(8)}$ Theory requires a set "covariantly constrain...