BMW 3 SERIES GRAN TURISMO Owner's Manual page 238

Reference
Capacities
Fuel tank, approx.
234
Technical data
US gal/liters
Gasoline: 15.8/60
Online Edition for Part no. 01 40 2 960 574 - II/15
I n f o r ma t i o n P r o v i d e d b y :
Notes
Fuel quality, refer to
page 188