A quick calculation. My Alinta energy bill tells me that the 1,515kWh of electricity I used last qtr emitted 1,985kg of CO2-e, or 1.31kg/kWh. So a highway charge for the Leaf would emit 35.5x1.31 = 46.5kg.
160km in the ICE uses 8ltr of Diesel which produces 21.4kg CO2
Even a 378km maximum range comparison, the ICE uses 19ltr producing 51kg. Except that, in a real world situation (like the ICE) the range is 270km (less if the a/c is on) or 13.5ltr of Diesel, emitting 36.2kg.