It all depends entirely on how efficient your engine is, how fast you drive, when you drive, the route you take, the weight of the car and of course the type of car used.
Greece - we assume is Athens.
We are also taking a ferry from Italy to Greece and not going via Slovenia, Croatia and Albania
However, taking a "normal" car, driving normally and getting on average 40 miles to the gallon.
The trip is about 1,700 miles so that would be 42.5 gallons
http://www.convertunits.com/drive/from/Bristol,+United+Kingdom/to/London,+United+Kingdom
It will take just over 4 hours to drive to Plymouth from London and about £45 fuel cost
a lot
It will cost approximately $22, for gas, to drive to Manchester from London. The cost will fluctuate daily. With the price of gas.
Nothing, airplanes don't use petrol.
how much petrol will a car use (enginne two liters)
Drive and see how long it lasts.
50p
150
That depends a lot where you start your trip.
300 dollars
About two hours but much depends on which part of London you are driving from.