Sarah
I think you need to get clarification from the DWP, especially if you will be earning near the limit, you cannot assume that the DWP will permit the allowances although I can't see why they would not,, especially for something like petrol where the allowance may not be a direct reflection of the usage.
Gordon
If you earn more than the allowed amount, even by a penny then your ESA claim can be closed as you will be classed as being in remunerative work.
Nothing on this board constitutes legal advice - always consult a professional about specific problems 
