I'm not a Mobil fan but I would think that anything that lubricates the the motor "better" would reduce friction and thus improve economy. Mine increased negligibly of maybe ~1 MPG.
You might want to consider doing the MPG manually by resetting miles when you fill up and next fill up see how many gallons you need to fill it up. The DIC has a habit of not being accurate.
You might want to consider doing the MPG manually by resetting miles when you fill up and next fill up see how many gallons you need to fill it up. The DIC has a habit of not being accurate.