Thanks jtsanders. Yes, I have an incredibly detailed budget. The budget item for the rental car was $6k. Gas was about $1350. I have other items for food, hotel, compensation for subjects, etc.
It sounds like you’ve covered all your bases. Not surprising for a PhD candidate. Congrats, by the way.
I still vote for option 1, with the lease option being the absolute worst option, because of the mileage charges and because of the requirements of the leases. It’d be a shame to have to spend $1K of the grant money to get a minor ding fixed, and a lease will require you to do so. The money in leasing is largely in fees and other required costs. I’d want to avoid that.
I assume that this is a direct grant to you that did not go through your university. This, then, allows you to choose how you spend the transportation allotment in the grant. My question with option 1 is this: Is this a vehicle owned by your university that they are renting to you or does your university have a special agreement with a rental agency that cars can be rented at a special rate for the university? I know that my university maintains a fleet of vehicles, but if the university vehicles are all checked out, the university has an agreement with Enterprise and provides a car for university travel. If this is a vehicle owned by your university that will be rented to you, it may be a vehicle that was slated to be turned in on a new vehicle and your university is squeezing another year by renting it to you. In this case, the reliability might be questionable. Even if the university is responsible for the maintenance, you don’t want to be stranded somewhere. If there is a breakdown away from the university, how does the university handle this. Do you have permission to get it to the nearest dealer?
Option 1 may be the best, but ask some questions.
Thank you both the same mountainbike and Triedaq! I will check into the lease options more closely. We had dinner with friends last night who were extolling the virtues of leasing. (Of course they lease luxury vehicles so that’s maybe an entirely different scenario when it comes to maintenance being included …)
Yes, the grant is direct. I will check about how the university handles it’s monthly rentals, asking specific questions about the likely age of the vehicle, who owns/maintains it, and reliability (e.g. roadside assistance). I would have never thought to ask about that. Thank you!
Oh and thanks mountainbike. It’s been a long haul. I took time off when the boys were little and while my husband finished law school. The grant-writing success has been a nice affirmation of my choice to come “back” 
Toyota has included scheduled services for the first 2 years so you could lease a Corolla for 2yrs and decide then if you can afford to buy the car (if you wish) also VW and possibly a few others but those are the two brands that I can think of at the moment.
Pretty much agree with @Texases. For the price you would pay to lease, just buy a used Corolla or Civic as they are very likely going to be easy to sell if you wish later. If you are careful, and can spend $8 to$10k, you are likely to get a reliable one. IMHO, that would be the way to go if I were you.
We inherited a Saturn for our daughter, fixed almost anywhere, 2002 it is, you might look at buying one with low mileage using it and reselling it.
Are you comfortable with owning a car and maintaining it to reliably fulfill the requirements of the research project? I could keep a beater running for 18 months but might need a lot of help doing the research. Maybe you’re up to both. If not the rental from the university leaves you free to take care of your primary responsibility while leaving the school responsible for keeping you road ready. I would advise checking on the insurance and posting back. A 3 year lease would likely cost more than the rental and a truly reliable car would likely cost well over $10,000 and might require a new transmission($2,500) in 6 months and sell for $2,000 in 18 months.
“Yes, the grant is direct”.
@jloA2–The university where I taught for 44 years did not like direct grants as it raked 46% off the top of the grants that came in for “overhead”. Be sure this is a way for your university not to make up for its lost overhead on your grant. I think it is especially important to determine whether your university is going to send you out with an older vehicle from its fleet or whether it has an arrangement with a rental company.
Some years back, I had a colleague that managed to secure a large grant. She found out what the university would charge to administer the grant and was able to have a local bank administer the grant for a lot less money. The director of the research office was livid when word got out about what my colleague had set up.
The college I retired from didn’t allow direct grants. I had to go through the proper channels, but I really didn’t mind. It gave me the power of the college’s name and connections as well as the use of college resources such as the profs, facilities, and equipment. Besides, I always preferred being a part of a team to working alone. I need the reinforcement that the opinions of others offers on decisions. They always see things that I missed.
But, then, I’m referring to grants applied for as an employee of the college, whereas my impression is that the OP has received a grant relative to her PhD work. It ain’t the same.
There I go comparing apples to oranges again. I guess I retired not a moment too soon… {
Have you looked into car sharing services, ZipCar being the largest? Their pricing model might work pretty well for you. You pay a price per quarter hour, but with that you get some mileage. If you exceed the miles that came with your hours, you pay extra for them, but it doesn’t sound like you’re going to be driving a whole lot of miles. There formulas differ somewhat from city to city, so I don’t want to be specific, and you may not even have them in your community. Here we also get some of the overnight hours free if you have the car in both the evening and the folliwing morning. Worth checking out. We went car-free for eifht years, relying on ZipCar, and had very few problems. You get to choose the car you want (subject to availability), and the cars they have are practical compacts. They pay for insurance and gas (there is a credit card in the car).