14½ years of car ownership
(part II)

This is the second chapter in what I thought would be a one-time exploration of the cost of owning a car. If you want to get caught up, read the first part. There I look at the total cost of ownership broken down by category and the car’s fuel efficiency, as well as the elasticity of my behavior relative to gas prices. (Spoiler alert: I’m fairly inelastic, or so I thought.)


# Digging in on maintenance

I recently took my car in for service — to get the oil changed and the brake pads replaced — and I was curious how my maintenance costs have changed over time.

I have been very good about taking care of my car. I get my oil changed regularly, but because I don't drive very much, “regularly” has sometimes meant every 3000-5000 miles and sometimes it has meant every few months. Apparently, I went the entire year of 2008 without changing the oil. As it turns out, I only drove 1,865 miles that year.

Purchase price
Service costs

The chart below shows my maintenance costs over time. This includes regular oil changes, standard recurring maintenance, and pretty much whatever has been recommended to me. I may be na├»ve, but at least my car is kept up. I should also point out that all standard maintenance has been done at Acura dealerships, and there have been a few repairs performed at independent body shops. I once had a rat make its home in the engine compartment, and I had to get some expert cleaners to do some pretty serious work on the car. Picture the body odor episode of Seinfeld — The Smelly Car.

Green dots are individual maintenance events. Hover over to see what was performed.

I figured that the maintenance costs would increase over time, because as a car gets older, you typically need to put more money into keeping it running. My car is no different, but I had one event early on in my ownership that throws the data off entirely. Someone ran into my car when it was parked, and I had to get the quarter panels on the left side fixed. That cost $1,970.21, and it skews the otherwise “up and to the right” slope of my maintenance costs, which you can see more clearly in the orange line, which ignores that event.

I had a suspicion that the good folks in Chevy Chase were somehow ripping me off with respect to my maintenance. They seemed to recommend a fairly substantial amount of service each time I would go in. You can see that in the short time I lived in D.C., which is highlighted in blue, I had the two largest to date maintenance expenses — replacing my tires, clutch, and all fluids. While the services were the most expensive I had incurred to that point, they did come after driving the car across the country, and in the 50,000 total mile range. Perhaps they were fully justified.

# Service Consistency

I think I am good about keeping my car maintained. What does the data tell us? My median days and miles between service are both pretty low, compared to standard recommendations of every three months or between 3000 and 5000 miles. I have been servicing my car more often than might be needed.

Days between service
Miles between service

From the looks of the chart below, I am also inconsistent in my service record, varying between short and long periods between services.

Miles since last service in orange; days since last in blue.

# Miles Driven

As I compiled my service records, I captured the odometer reading at each one. With that information, you can see how consistently or not I drive my car.

My insurance premiums are discounted, because I claim that I do not drive very much. Fortunately, the data proves it out. I drive only 5,329 miles per year, compared with the average that falls somewhere between 10,000 and 18,000, depending on whom you ask.

Total mileage
Annual mileage

But, I was interested in seeing if I have been consistent in my use of the car. Remember in Part I when I wanted to see if I changed my behavior when the gas price skyrocket in 2008? Now I have more data to find out.


The peak gas price occurred on July 8, 2008, as shown in the chart. By the looks of it, I did in fact drive less — only 1,865 miles total in 2008 — but whether or not it was because of a conscious decision based on gas price, or because I was flying back East for work more often, or because I was driving my girlfriend’s car more than mine, we will never know. Most likely a combination of all of those.


# Caveats, Mistakes, and Mea Culpa

See the caveats, mistakes, and mea culpa from part one. They are all the same.


# Sources

Driving norms in 2000
Driving norms in 2015