Home › Forums › Stay Dirty Lounge › Service and Repair Questions Answered Here › 2012 Ford Edge 3.5 poor fuel mileage after changing plugs › Reply To: 2012 Ford Edge 3.5 poor fuel mileage after changing plugs September 22, 2023 at 4:34 pm #1026301 Rahul JonesParticipant Check your tire pressures. If okay, try taking some sharp corners then stop and smell around the vehicle. If you smell fuel there are chances of fuel leak from the top of the fuel tank.