[Dr Graham]

I have another reason for keeping as lttle petrol as possible in my car.
I don't have a garage or secure parking place, so I reckon that my car is less likely to be stolen if there is very little petrol in it.
This is especially true in the case of the so called "Joy Riders" who steal vehicles to thrash around in, and then abandon and usually set fire to them after they have crashed them or wrecked the engines.

Another reason for not leaving much fuel in the tank, is Insurance Companies do not include things like fuel when calculating how much Compensation to Pay Out on a Stolen Vehicle Claim. With the current Obscene price of fuel in the UK, that could equate to an uninsured loss of over 100 GBP.