Comment by jollyllama

I had a 2004 Citroen, which needed the front sidelight bulb replacing, after investigating for 20 minutes, decided to ask the garage how much it would cost next time it was in.

Since Dante wrote _The Inferno_, there has been a circle in Hell added where car designers are endlessly changing the spark plugs on AMC Javelins, bleeding brakes on Ford Escorts, and similar maintenance tasks which the design made more difficult than is reasonable.

Had to help a fella replace a battery in what I believe was a Mitsubishi... had to remove the front tire and the wheel well liner first!

Dang

The Ford Maverick (2022+) requires removing the air intake to remove the car battery. This is fairly common across many new car models.

Right but what I'm getting at is that there can be tradeoffs that might make designing for maintainability mean optimizing for something less important to the end user.

Do you optimize an engine for how easy it is to replace a filter once or twice a year (most likely done by someone the average car-owner is already paying to change their oil for them), or do you optimize it for getting better gas mileage over every single mile the car is driven?

We're talking about a hypothetical car and neither of us (I assume) design engines like this, I'm just trying to illustrate a point about tradeoffs existing. To your own point of efficiency being a trade with durability, that's not in a vacuum. If a part is in a different location with a different loading environment, it can be more/less durable (material changes leading to efficiency differences), more/less likely to break (maybe you service the hard-to-service part half as often when it's in a harder to service spot), etc.

Glad to know in this hypothetical car scenario the owner decided to not get an oil change leading to the total loss of the vehicle. That seems very realistic and definitely something that car designs should be optimized around.

Or, we consider that 2mpg across 100,000 cars can save 3,500,000 gallons of gas being burned for the average American driving ~12k miles per year. And maybe things aren't so black and white. You're argument, in this hypothetical, is that negligent car owner who destroys their car because they're choosing to not change the oil is worth burning an extra 3.5millon gallons of gasoline.

Sorry we're talking about a hypothetical car engine, and as an analogy to software development. I'm not an expert in designing car engines like you, but acting like this example being not fully realistic is some kind of "gotcha" for the point I'm making is really frustrating.

The point that I am making (obviously, I think) is that tradeoffs exist, even if you don't think the right decision was made, your full view into the trade space is likely incomplete, or prioritizes something different than the engineers.

Based on the replies, saying there's a hypothetical 2mpg improvement to be had was a mistake, everyone is latching on to that like there's some actual engine we're investigating.

> We don't have magic oil filters which last even 22k miles. You should be replacing them every 6 months / 6k miles, or 12 months / 12k miles depending on your risk tolerance (some people suggest even half my short interval).

We do - they are just a lot bigger.

You should replace the oil filter when it is no longer filtering. Replacing it early is a pure waste of money. Unfortunately the tests of do you need to change the oil filter is more expensive than just replacing the filter so just replace it before it can possibly be clogged is the right answer. Generally the manufactures recommendations are correct and you should follow what they say unless you have lab results that say otherwise.

I'm just gonna copy and paste a response to another similar comment: The point that I am making (obviously, I think) is that tradeoffs exist, even if you don't think the right decision was made, your full view into the trade space is likely incomplete, or prioritizes something different than the engineers.

Putting some random number of hypothetical mpg improvement was clearly a mistake, but I assumed people here would be able to get the point I was trying to make, instead of getting riled up about the relationship (or lack thereof) of oil filters and fuel efficiency.

> You should be replacing them every 6 months / 6k miles, or 12 months / 12k miles depending on your risk tolerance

You should be replacing your oil filters based on the manufacturer’s service schedule, there’s no rule of thumb. Look at the service manual, my car has the filter change scheduled every 10,000 miles.

Mazda has historically been very good at designing for repairability. My (latest) Mazda is ten years old, so I cannot verify any model later than that, but it's one reason I've been brand-loyal for decades. The 2015 CX-5 puts the oil filter right next to the drain plug, slightly recessed (for protection, I assume), but with ample clearance around it for tool and finger access. It's the best thought-out oil filter location I've ever seen; I cannot think of any possible improvement. The advantage of that, over Subaru's choice, is that the oil in the filter can only ever spill into your drain pan (or I guess the ground, if you're a numpty), never into your engine compartment.

That is fine if you are say building a race car that will be essentially rebuilt anyway in between races, or in general where 0.1% extra performace/less weight from non-repair-friendly placement might be worth it.

Not for normal car

The US is filled with bubble cars like everywhere else. There isn't really much difference between cars across the world. Well, China is unique with like 100 automakers all searching for customers, but for most of the world, it's Toyota, VW, Hyundai/Kia, Stellantis, GM, Renault/Nissan, Ford as the top global producers and they sell everywhere. Sure there are some special models in local markets, but those are mostly rebadged versions you can get elsewhere.

Fun Fact: Along with the "Bees are disappearing" scare, which was just measurement error, there has been an "insects are disappearing" scare, due to the fact people's windshields are not covered with bugs like they used to be. However that is because cars have gotten more aerodynamic so fewer insects are hitting the windshield.

I think oil filter located somewhere sinful usually in cars that are aerodynamically sound.

Between rebuilding an engine and disassembling a bumper to replace a lightbulb most mechanics would genuinely rather be doing the lengthy but interesting work of rebuilding an engine than the lengthy and fucking boring task of disassembling a bumper to fix a lightbulb.

ChatGPT, write me a 2010-style Hacker News front page essay about how software maintenance is just like automobile maintenance, and why nobody wants low-value maintenance work to be arduous, failure-prone, and boring.