Contrary to EPA mileage numbers, you get your best MPG on high speed non-stop highway runs. And you will get your worst mileage on 'cold start'; short; low speed drives like you have on your commute to work. It takes a mile or two before the cars engine and catalytic converter warm up and the car can drive on battery alone.
If you do repeated short trips and don't let the engine cool down much, the MPG will get better, but it will never be as good as long steady drives at 50
MPH or higher.