As a test tonight i have placed some carboard underneath the engine block to see if there is any signof a fuel leak, can anyone suggest anything what could be causing the increase of fuel usage..


Just to recap I have a S Reg 406 SRI 2ltr turbo (petrol) with 103,000 on the clock
EDIT:
To add more info the front end bump caused the aircan rad to have a decent size bow in it (tbh i cant see how this would cause the fuel usage to go this bad) the aircon has never been charged since ive owned the car and no gas esacped when i had the bump.
The main radiator got replaced with a new one just after the car was purchased, this has a very slight misalignment but nothing to worry about.