I have been measuring the mpg weekly when I fill the car, dividing the amount taken to fill the car into the miles since last fill up. This is working out at around 27 mpg. I have been driving the car for 5 weeks. I am an experienced driver and am not abusing the car. My last 03 Ford Mondeo 1.8 was giving me more than 40 mpg. Is there a technical problem that I can tell my garage to fix? it seems really strange that a newer model is giving less mpg.