My Fiesta with EcoBoost 100 averaged 48.5mpg on one long journey, while the on-board computer shows 37.4mpg overall, mostly on short local trips along fairly congested roads in suburban London. May I suggest to SM that he applies the handbrake when stopped at lights or in stationary traffic? The engine will switch off until the clutch pedal is depressed to restart it. I have often observed five cars out of six in a queue with their brake lights on, indicating that the foot brake is being used.