\version "2.18.0"

{
  %\override Staff.MeasureCounter.staff-padding = #4  doesn't work
  \override Staff.MeasureCounter.outside-staff-padding = #2
  % \override Staff.MeasureCounter.count-from = #2     %this works
  \startMeasureCount    
  \repeat percent 4 { g''4 g'' g'' g'' }
  \stopMeasureCount
}

\layout {
  \context {
    \Staff
    \consists #Measure_counter_engraver
    % \override MeasureCounter.staff-padding = #4  % doesn't work either
  }
}