I recently changed my air filter, probably a bit later than I should have. I have noticed reduced fuel consumption (the plugs were a little black) and better acceleration. Clearly this is all because I am now drawing in enough air to burn all of the fuel properly. So i wonder, do the so called performance air filters actually make any difference ? is it worth fitting one ? I saw one claiming that it allows twice the air flow - I assume they mean half the pressure drop across the filter for the same air flow bearing in mind that at twice the airflow you have 4 times the pressure drop etc.
TC
Warm air doesn't warm up the engine, it just makes it inefficient. You should get your car serviced by a Ford dealer and with that mileage you will get it back with as-new performance.