If you get a car in good condition, it should get you though the grad school. However, the urban and suburban fuel economy is kind of scary. I get 16mpg or so. Ok, this may not a big problem for a typical grad student who lives next to campus and doesn't have much time to do things outside of school. In grad school, there were times that I'd drive my car only once a week to the gym and to get groceries. However, for a daily driver, I'd look for something else. Perhaps a compact car, or a midsize car with a more modern drivetrain. Gen 4 Taurus has effectively the same drivetrains as the G3 which debuted in 1995. If you have to drive a lot, a compact car could work better for you. A 2006 Toyota Corolla or a Mazda3 should probably cost about the same as a Taurus in a comparable condition.
I got a low millage 99 Taurus (built in late 98) in 2005, a new set of tires, and a battery. I was also in grad school, so I didn't drive it much. Maybe, 20,000 miles in five years. For the first five years it was virtually trouble free. I only changed fluids and filters. After 2010 there were some troubles, despite the "low" millage:
outer (or inner?) links
brakes are shot, front and rear
and possibly one of wheel bearings
A lot of these issues are relatively expensive to repair. When in grad school, for me it was a big issue to drop even $500 on any sort of repair work, much less the $800 which was the cost of replacing the steering gear and other parts that came out worn. However, the engine and transmission are running strong. I am slowly taking care of other things. Once this is done, I expect the car to be relatively trouble free for another five years.