Hello and welcome to the site.

First off, is there any check engine light or any issues with the car?
Second, what is your typical commute like? If its really short distances in cold weather hwere the car never gets warm, 10.5mpg is not surprising. If its long trips you definitely have something wrong with the car.

If this is your first fill up with the car, I'd drive it more and fill up again to make sure you actually only got 10 mpg.