The short answer is that the technology of the odometer pre-dates any ability to track the speed/ torque usage of the vehicle. As such, the “miles only” odometer is the de facto standard. Modern cars could have more meaningful metrics, but there is no requirement to add such a thing, so manufacturers don’t bother.

In the absence of a better aggregate indicator, the mileage is a good first approximation for how used a car is.

Of course it is no replacement for a service history and a good pre-purchase inspection.

>why there isn't a metric to distinguish between used cars that have been driven in an urban setting as opposed to highway cars where there is clearly a larger wear and tear Factor due to the fact that the miles placed on them are more strenuous miles on the car as opposed to a clean highway mile that affects more than just the engine output, we have it more gas mileage

Both - among others - are important and entirely separate metrics. Knowing the circumstances under which a car was driven is pointless without knowing the mileage. Knowing the mileage is pointless without any other data. A car's literal age is yet another important metric that has nothing to do with its mileage but is determined by looking at its build year.

There are dozens of other things that are important for determining and putting into context the condition of a used car. And any salesperson will provide you with the necessary details, not just the mileage.

There is. It's called "going to the mechanic to check if the car is in a condition as advertised".

Mileage is a fairly reliable measure for the expected state of the engine/drivetrain of the car. The parts that, if worn out, usually get the car scrapped, because replacing them would be as expensive as buying a working car.

I would love to hear from someone who'd replace a broken driveshaft or a wrecked engine on a Toyota Corolla.

Mileage on a car is really more an indicator of wear than "age" of the car. The car does not have the ability to log "city" vs. "highway" mileage. So you, the buyer, need to look at the age of the car and the number of miles on it and decide for yourself how much wear you think the car has.

If the car is 5 years old and has 150,000 miles on it, obviously those are highway miles because the highway is really the only way to put 30,000 miles on a car in a year. On the other hand, a 5 year old car that has maybe 60,000 miles might have spent all of its time in city traffic. Taken in combination with the overall condition of the car's interior, etc. you can get a pretty good idea of how it was used and how worn it is.

I realize that's how it is. My question is why.

I think this is the answer I'm looking for. Basically, it could be useful but we just stuck with it. Thank you for your response.

Right, so the part that confuses me is that we can look at mileage and say oh it had every 5,000 miles or 3,000 miles another oil change but this literally does not take into account the fact that this car could have sat idling for many many hours very often. And there is no metric to determine engine output. It just seems like a vital detail that is missing.

While what you say is true, mere idling won’t put as much strain on the chassis, cables, suspension, transmission, etc.

Less parts moving = less wear usually, so the metric will hold as well as it can. I suppose you could rate it in hours, like an industrial machine, but that would be a sketchy metric as well. Did you just turn the key, or was the engine running?

This is clearing things up for sure. Don't motorbikes or bikes get rated by hours used? But yes I'm beginning to understand this better.

Maybe partial logic is that a majority of cars have a balanced average amount of highway versus Urban miles?, And that this metric is in fact truest in the sense of modern technology too?

Sorry my articulation is a little fuzzy today.

>Tires shocks and brakes all of these other things are usually repaired within a certain cycle of mileage, but the major indicator trying to figure out if a 50,000 mi which car versus 150,000 mileage car, could be incredibly different if I lived in a very urban area and perhaps sat in my car with the engine running for several hours. I'm just confused why this never was taken into account but it seems like from one of the answers that this is kind of just been the de facto standard and hasn't really ever been updated.

Highway miles are easier but only a little and it still depends on soo much. A car with 60k miles driven on a nice highway may be in better condition than one with 50k driven in the city but one with 50k driven on crappy bumpy highways may be in worse shape than the one with 60k city miles in a place with nice roads and no salt. A car with 100k highway miles is still wayyy closer to the end of its life than one with 50k miles of any variety

Each bump, vibration, start, and stop stresses various systems. Highway speeds are easier on the engine and transmission because they're staying in their happy zone but higher speed bumps are harsher on the body and suspension.

The mileage is just a guideline as higher mile cars are in general closer to the end of their life, but you really can't capture all the little differences which is why there's also a quality grade for the condition of the vehicle and you should get it checked out.

You fundamentally cannot make a perfectly accurate pricing tool for cars, there are wayyy too many variables for someone to punch in which is why you generally get a price range and there's a qualitative assessment after that.

Actually my ebike is still miles. Miles = moving parts.

Motorcycles in the US are also miles im 95% sure. You will see hours on things like tractors I believe or ATVs, even watercraft.

It’s really hard to gauge the overall health of a vehicle via one metric. Just because the car has 5000 miles on it doesn’t mean the previous owner didn’t do them all at 6,000 rpm in second gear for all you know.

This is also part of the reason quality electric cars have decent resale value after hundreds of thousands of miles at times; the drivetrains have many less moving parts than internal combustion engines, so the overall health of the vehicle is suspect to much less “witchcraft”.

In practice it seems good enough for most cars. If you have an extremely special use case (eg. a police car idling by the side of the road all day), your mechanic will take that into account.

Planes, by the way, use hours, takeoffs/landings (the number of those is assumed to be the same) and, for big ones, pressurization cycles.

Some cars kinda do have that. If they display engine hours you can get more of an idea if a car either idles a lot or does a lot of city driving if the miles are low but the hours are high. But this is much more common in diesel vehicles

Try and propose a different metric. Guarantee it's basically impossible to standardize.

We use mileage cause it's all we got.

Exactly!

Hey that's really interesting I did not know that. Thank you

It's not. See other comments.

I've never seen it. Can you share a resource?

Interesting. In NYC I've always felt like 30,000 cars from Brooklyn are equal to 100,000 cars from nicer areas in Jersey. But yeah, I totally get what you're saying in the grand scheme.

Highway mileage is easier on a car (generally) than urban mileage. Even manufacturers note this in their owners manuals, specifying that earlier service schedules for urban driving are a requirement.

Hence my question :/

But also your statement indicates that the flagging on my post is inaccurate and isn't a false premise so thank you for that

Your question stated that highway miles were harder on a car. That is the false premise (I'm assuming).

It's an awful run on sentence more wear and tear was referring to the urban miles. But yeah. My bad

30,000 miles is only 120 miles a day driving on business days. Only driving 6 hours a day, that's an average of 20 MPH. Not too hard to keep it in town.

The general intent holds, but it's surprisingly easy to put alot of miles on.