BMW operates on a 7 year model cycle, with a refresh usually occuring at year 4. The original 1er came out as a hatch in 2004 so it was just redesigned for 2011. The coupé and cabriolet came out in late 2007 and recently went through a refresh, so you can expect the next generation to came out around late 2014. Simple math.
Current Ø consumption: