Hi,
apologies for the late reply but been busy at work.
My QQ does about 430km/33L of petrol in Lahore without AC.
partially - basically the 800cc engine does run a little hot on petrol but what kills it here is our hot climate combined with CNG (Natural Gas has a higher calorific value (heat of combustion) than gasoline). In my case engine needed overhauling after 70k driving on CNG, needless to say i've sold off the CNG kit and running it purely on petrol now.