I agree with all the above posts, you should really try and live locally if at all possible. I appreciate that on-site costs are prohibitive for you, so why don't you use the power of pprune or the OATS website to hook up with other students to arrange accomodation. It works out a hell of a lot cheaper, you will have other brains to help you with any ATPL problems, you can party whenever you want, you wont be affected by the Algerians (as lovely as they all are) and you will save a hell of a lot of fuel, time and frustration.
As for your £55 budget for fuel, what about tyres, brake pads, brake discs, clutch, oil, bulbs, cracked lights or windscreen, or any of the many other things which can go wrong in a car with high mileage? These are things which, especially if you do not have a warranty for your car, you cannot ignore. However, the real killer will be if you are involved in an accident (some of the people around here just cannot drive) - that could cause you untold expense not to mention severe difficulty in getting to Oxford. Remember, driving in rush hour can seriously tire you for class and for study, do you really need the stress?
On a final note, I'll leave you with this - one of the guys in my class worked out that during groundschool his commuting distance was equal to him having driven all the way around the world....... that's a LOT of miles!!!
VC10 Rib22