D.C.
Ok, this is probably more info than you need, but I put it all in for first-time drivers who may read this :)
I haven't driven one of these or owned one, but I looked up the gas specifications of it. Your gas tank should be a 23-gallon tank. When it was new, it should have gotten about 14 miles per gallon in the city (also known as stop-n-go traffic) and about 19 miles per gallon on the highway (this does not count when stuck in bumper-to-bumper stand-still traffic since the gas is wasting away while not moving). If the vehicle has been well taken care of then the gas mileage should still be close to the brand-new rates. So, you should be getting about 322 miles per tank on daily stop-n-go (city) driving and about 437 miles per tank on highway driving. If you have the original owner's manual or can get one or call a dealer, you can find out if this is correct since I got tank size off of the internet.
To find out how much YOU get on a tank, here's what you should do: a) Fill your tank completely; b) Zero out your trip odometer (measures miles driven in one trip, not your speed); c) do not fill up again or zero out the odometer again until your gas warning light comes on; d) write down how many miles you drove on this tank; e) mark whether this was city or highway driving and if this was a "regular day" amount of driving such as do you drive this way normally or if you drove more than normal; f) when you fill up after the warning light comes on, write down how many gallons it took to completely fill your tank; g) subtract the gallons it took to fill your tank from the # of gallons your tank actually holds and this is how many gallons you have in reserve when the warning light comes on. After a few times of this you will know how many gallons on average you will use before the warning light comes on and how many spare gallons you have when the light comes on.
To find out how many miles per gallon you got for that tank, divide the number of miles you drove by the number of gallons you used: lets say you drove 290 miles on 20 gallons: 290 miles divided by 20 gallons = 14.5 miles per gallon.
By zero-ing out the odometer EVERY time you fill up, you will also be able to look at how many miles you drive on a regular basis and say "oh, I have so many gallons left, so I can go so many more miles to get to a gas station". The warning light is what some folks call "sucking fumes" because if you're not careful you'll end up stuck on the side of the road. You'll also be able to average out how many times you fill up between paychecks, how much gas you buy and how much it costs each week/month/year so that you can write it down on a budget plan or how much money to plan for if you're saving for a trip.
Here's my vehicle info to use as an example: I have a 1995 Mazda Protege, a small car. I live in NE San Antonio. For me, my daily driving includes stop-n-go driving and some highway driving on I-35, Loop 410 and Loop 1604. My tank holds a total of 13 gallons and my warning light comes on when I have 3 gallons left. I get 26 to 30 miles a gallon with city driving. When my warning light comes on my odometer usually reads between 280 & 300 miles per trip, unless we've been out driving on the highway more than on city streets and then we get more than 300 miles to 10 gallons. This means I have 3 gallons left on average and 70-90 miles to find a gas station.
Good luck and I hope this helps someone :)