Why does my mustang 2002 waste so much gas?

I Have a mustang 2002 ford v6 base and i had recently bought it, and it waste so much gas. I use it to times today not for very long and its already half tank. Is this normal? And if not what may be causing it to waste so much gas?

V6 engine takes a lot of gas…

Does it have misfires? Is the air filter clean I drive 20 miles a day and my f150 4.6 won't even drop much it will be at half a tank in 3-4 days from full depending on how I drive. It usto have misfires and be horrible on gas till I put new coils in. Have auto zone. Also if you have your engine service light on have them check to see if it is a misfire or you could change your spark plugs that will help a little

Vague numbers.

Fill the tank and take note of the miles.
Drive around for a while.
Refill and take note of how many gallons, and the miles travelled.
Do some maths to get the actual MPG.
Compare this to what it should be and see if you have a problem.

There's also the way you drive. My car can over 30mpg on a light foot. ~20 if I'm heavy on the jandel.

Small engine in a big lardy car is never going to be economical. Short journeys also will not be economical and also how you drive it will make a huge difference.

Before you conclude its wasting fuel it might be good to actually measure the usage as suggested by Ianab. Also consider that the gauge itself may not be registering the exact amounts of fuel in the tank. Most gauges are at best an estimate and usually move faster through certain areas of the gauge than others. In your case that may be the case at the upper end of the scale.

You are using inefficient oil in it! The use of MOBIL ONEW-30 oil and have your throttle body and idle air control valve leaned up to showroom clean! All FORDS are made to teh highest standards