The AA calculate that it costs around 67p a mile to run a typical familly car such as a Ford Focus based on 10,000 miles a year.
Escalating fuel and insurance costs contributing to the increase.
Yet using your own car for work ("Business use") the reinbursement is set at 45p (for thre first 10,000 miles).
The rate only recently being raised from the historical 40p a mile.
So using your own car for work you subsidise your employer to the tune of 22p for EVERY mile you do on firm's business!