@shqamar
since u said u r paranoid about ur car therefore capsat's reply should get u satisfied.other then that if u leave her like that then i guess it wont do any harm to ur car.
OIL in fuel tank ??? damn, - Hi-Octane 5 liter to 80 liters diesel i have seen truck drivers doing in Hilly terrain, but oil in petrol tank is only for 2 stroke in old fashioned vespa rickshaws. Not in motorcars.