Is my Car Getting the Gas Mileage it Should?

I just bought a 2013 Ford Fiesta SE, and I'm having some concerns about the gas mileage. The Fiesta supposedly gets 29 city and 39 highway (when in reality I get around roughly 27). It has a 12.4 gallon fuel capacity.

What is getting me worried is the fact that today I drove to my family's house (40 miles from where I live), and it ate up 1/4 a tank of gas, and it was on full when I started. Is this normal? The car is still under warranty, is this anything fixable?

Thank you for any help, as I'm by no means a car expert.

If you do not have a display of instantaneous or ave. Mpg, set your trip odometer when you fill it up, then next time you fill it up make a note of the gallons and trip odo reading and reset the trip odo, and do the math (miles/gallons).

It depends upon how you drive, whether you are using air conditioning, etc.

You are quibbling over two miles BASED ON AN EPA ESTIMATE?! Jeezus, you need to get a life. Now, if you were getting 19 mpg, then we can talk. Check the air filter, fuel filter, plugs, air pressure in tires…

It depends upon how you drive, whether you are using air conditioning, etc.

Something is wrong. If you have a 12.4 Gallon tank and it used 1/4 (3.1 Gallons) At 27 to the Gallon that should have taken you 83.7 Miles (City) to 120.9 (Highway) That journey should have used from 1 Gallon up to 1.3 Gallons. Before you do check you have it on Miles not Kilometers

Andy C