I've been putting this post off a bit it, because a post about family logistics is a bit of a silly way for people to learn that we're expecting a third child, and I kept thinking I would write something else first, but I didn't. So: with another child coming, in June, I'm thinking about, among many other things, cars.

My parents always had two cars; given where we lived, where their jobs were, and the kind of jobs they had, there wasn't anything else that would've made sense. I was never very excited about driving: I put off getting my learners permit for over a year, until eventually my aunt learned that I still didn't have one and told me she was taking me to the RMV and wasn't going to take no for an answer. I learned to drive, but once I got my license I was back to not driving: putting me on the family car insurance as a teenage boy would've cost thousands of dollars a year, and I could mostly take public transit places.

As an adult, I've been able to live in places with good public transportation, close enough to bike/scoot to work, or both. Even as we got more settled and had two kids, not having a car hasn't been a problem.

With a third kid, though, we're thinking we probably will get a car. Various reasons:

  • Once there are five of us, we no longer fit in a car someone else's driving (standard taxi, getting a ride from a friend).

  • There's not really a safe way to move a baby on a bike, and once they're older you can't fit three in the trailer.

  • We're generally more willing to trade money for time and convenience than when Lily and Anna were babies.

  • It's really nice to have the option to go somewhere on short notice, and many places we might want to go are much more practical my car.

I was curious how an approach of "just use Uber whenever we would drive if we had a car" would compare, since we wouldn't use a car a huge amount. We thought through our likely car usage, however, and that wouldn't make sense. When you take into account that we wouldn't fit in a 5-seater if someone else was driving us (though we would if when driving ourselves), this would be over $5k/y.

We have a driveway, and while it's a bit awkward to hold two cars it's not that bad for something we wouldn't use often.

If we do decide to get a car, there are a lot of options! Considerations:

  • We're planning to drive a pretty small amount (~5k/y), so things that pay off in proportion to the number of miles you drive are (while still positive) less important to us than to most prospective buyers:

    • Electric cars letting you avoid buying fuel.

    • Newer cars being safer than older cars.

    • Driver-assist features like automatically stopping to avoid crashes.

    • Comfort, amenities, etc.

  • We're not dependent on the car for our livelihoods, so reliability is not a top concern. On the other hand, unreliable cars are unpleasant and stressful.

  • Needs to seat at least five people. While more than that would be nice, I don't think it's worth paying extra for.

I was initially thinking this pushed toward a used car, but when I look at how cars depreciate maybe not? For example, you could buy a new Honda Fit for maybe $17k and sell it in five years for $10k, for $7k net. Or you could buy a five year old one for maybe $10k and sell it in five years for $4k, for $6k net. It's a bit worse than that, because the new car ties up more of your money which you could invest, but on the other hand repair costs for the older one should be higher.

Estimating over a 5y timeframe:

  • Depreciation: $7k
  • Insurance: $7k
  • Gas: $2k
  • Repairs: $1k
  • Total: $17k ($3.4k/y, $280/m)

Other things we should be thinking about?

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I went through a similar process to buy my first car (although I wasn’t considering children relevant, I did consider a dog and skiing supplies, as well as wanting to be able to transport friends). I eventually settled on a $10k used car from a dealership. I was originally expecting to buy a very used $3k car, but was convinced to increase my budget by the idea that driving a maintenance-needing car would be stressful, as you note. Advice I received was that $10k was around the sweet spot for a car that could still go a long time without needing much maintenance. I ended up buying from a dealership, which I considered a worthwhile premium because I knew nothing about cars.

I also wanted 4wd/awd for New England weather driving (I wouldn’t consider this essential for boston, but driving to outdoorsy things in the winter is less stressful with this feature). Also wanted decent highway mileage, mainly for environmental reasons. I ended up getting a 7-year-old Subaru Outback with just over 100k miles on it. It’s been a year now and I’m reasonably happy with the purchase.

Depending on how old your kids are, you probably need more than 5 seats (or at least more than an economy size 5 seats) to transport everyone safely/legally/comfortably. Take your car seats with you when picking out a vehicle, and make sure everyone will actually fit (and that it's not a pain in the back to get the infant in and out).

I've put three car seats across the back of many small cars, including the ones we are considering like the Honda Fit. As long as your seats are reasonably narrow, it's quite practical. See https://www.lesswrong.com/posts/AgrxwzhkFWwbQrRuz

I'm not sure what you're thinking about in terms of "safely" and "legally"?


Ok, so this particular problem actually has a small number of correct answers!  Everything else is suboptimal!  

You want a vehicle that has minimum cost, is safe, and meets requirements.

Well, it's pretty easy, actually.  Look at this chart : https://www.yourmechanic.com/article/how-much-do-maintenance-costs-increase-by-mileage-by-maddy-martin

As it turns out this isn't even a decision.  The Toyota Prius, approximately 6 years old, is optimal.  That's because it has these characteristics:

         a.  Used cars are cheaper TCO than new cars (I have a spreadsheet proving this if you are interested)

         b.  Toyota is the most reliable brand on average

         c.   The Prius is their most reliable model

         d.  The Prius uses the least fuel, out of their used models.  They do have plug-in-hybrids that use even less fuel, but the good ones are 2021 model year and are not available used.


A Prius may not quite provide enough space, 3 kids is kind of a lot.  In that case, the same as above, just get the Rav4.  (but not the hybrid unless it's the 2019 or newer rav4 hybrid).  As a side note, while the Prius has been made fun of, the Rav4 is the most commonly sold vehicle in America next to trucks, so it's a decision that is well 'peer reviewed'.

Full disclosure: I read that chart above and bought a Prius 3 years ago.  It has exceeded my expectations.

I think you're not taking into account that we are not expecting to drive very many miles, and so per mile costs are less important to us than average?


In that case your costs are dominated by depreciation. So you want a used vehicle, one that has low depreciation, that meets your needs.

Toyotas have low depreciation but with your set of conditions, all sorts of gas guzzling boats like suburbans and escalades fit as well.

If you plan on taking long trips in the car, or if you plan to have it for ten or fifteen years, or if there is any possibility of a fourth child, you might want to consider a minivan. As the kids get bigger / trips get longer, putting three of them in the back seat of a car, with one uncomfortably in the middle, will get less and less comfortable.

If you plan on taking long trips in the car

I don't think we're likely to do much long-distance travel, no

if there is any possibility of a fourth child

While I don't think we are likely to have a fourth child, if we did we could sell this car and buy another one. It's not like moving into a rent controlled apartment!