[AnotherGoodName]

TPMS (tire pressure monitoring system) is a coin battery powered computer inside each tyre of your car. They’ve been around for a couple of decades now. Even the lowest end cars have TPMS in each wheel. If you change wheels you need to go to a wheel shop and have them re pair (as in re pair wifi) the wheel with your car. I had to do this recently with my 2014 ford focus.

Anyway those are just four of hundreds of computers in your car these days.

[throwaway27448]

Not exactly a great example as it's unnecessary and expensive to replace. Lots of other microprocessors actually make your car easier and safer to drive.

[dcrazy]

TPMS has been mandatory in the U.S. since 2007. It turns out riding on under-inflated tires is dangerous, and people don’t regularly check their tire pressure.

My car will not exceed a certain speed if TPMS is malfunctioning.

[_factor]

Conveniently it cost around $200 every 5-7 years to replace all 4.

[NetMageSCW]

Driven cars much longer than that without replacing TPMS.

[tonyedgecombe]

It amazes me that people don't notice. I was driving with a friend once and had to tell them to pull over because they had a puncture.

[xyzzy_plugh]

A TPMS doesn't make your car easier and safer to drive???

[throwaway27448]

You can buy a tire gauge at a gas station for $10 and check your tires when you clean your car.

But then again, I am old enough perhaps to have been taught to regularly check your tires before driving to begin with.

[sokoloff]

Did I just read an argument that it’s easier or safer to manually check your tire pressures rather than having the car do it automatically every time the car drives fast enough to “wake up” the TPMS units?

[throwaway27448]

It's easier to do that than to pay to replace them when the battery dies. Just stop adding more unnecessary costs to my car maintenance!

[bluGill]

That battery lasts longer than the tire. People sometimes try to say but I don't drive my car much and that doesn't change the math because tires are destroyed not just from the way of driving but also the sun and ozone in the air destroy tires it still needs to be replaced every seven years., it still needs to be replaced every seven years.

[jfengel]

The $10 gauge is of dubious accuracy. Especially if I bought it at a convenience store that happens to sell gas.

[izacus]

Some cars use ABS speed sensors instead of that which is usually a bit less accurate, but also less of a hassle.

[ExoticPearTree]

Yes. But in my car the downside is that it does not tell which wheel has a problem, just a generice message: check tyre pressure.

Real TPMS sensors inside the wheel give much more accurate information.

[procaryote]

That's a software issue rather than an inherent limitation. I've driven cars with abs-sensor based TPMS that will tell you which tire is under or over-inflated