One of the things I hate doing is taking the car in for maintenance. Even if the service representative isn’t pushy, I still feel like I’m getting scammed into paying money for no reason. I think the reason for this is because I don’t really know what I’m paying for.

The car industry reminds me a lot of the consumer computer industry – places like Future Shop and Best Buy will suggest that people buy extended warranties, anti virus protection, recovery discs, geek help, etc with their computer purchase. I’m sure a lot of consumers don’t actually know whether they need these services or not but are preyed upon and end up spending more money than is necessary. I feel like one of those consumers when it comes to cars.

Of course, I don’t want to feel helpless, so I try to never make impulse decisions and to do some research before committing to certain tasks. But I find it is very difficult to do research – I can’t (economically) experiment with my car to see the effects of my decision and I find the information I find online is biased. For example, I had to decide whether to do my timing replacement this weekend and did some reading online – the anecdotes were from people who suffered premature failure and those that repeated the standard line (replace it every 100,000km). The (perhaps silent majority) who had their timing belt last well over 100,000km hardly post at all; and why should they? They are quite happy with their timing belt’s longevity.

I ended up getting the timing belt replaced, because I had already put it off for almost 35,000km longer than I should’ve (obviously it didn’t snap). But it got me thinking about a recent article I read in Wired about designing for failure.

If you chart failures over time, you will almost always see some form of bell-shaped curve: A few units will fail early, most will fail in a cluster in the middle of the chart, and a few will last much longer than expected. Knowing when the first failures will happen is vital to guaranteeing reliability. On Ford parts, the very first fails aren’t supposed to happen until just after the 10-year mark (with most of them occurring much later).

I am quite confident that the maintenance guidelines for every single part are set so that the time limit is to the extreme left of the bell curve – it would be a public relations disaster if a car’s parts failed when it could have been prevented through a more pre-emptive maintenance plan. Of course that means that on average, you can safely go beyond that guideline without suffering failure. The trick, is that you don’t know the time scale of the curve so it is difficult to judge how much longer you can go (and the car companies will never tell you either).

Therefore in a way, the money that you pay for car maintenance is actually a form of insurance to ensure that your parts don’t fail. Except instead of the insurance companies having full knowledge of the statistical likelihood something will happen and charging based on that calculation, car manufacturers make you pay the full price for the part at pessimistic intervals, every time. That is an inefficient system, and a rip off.