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Ask HN: Why do they make cars go so fast if it’s illegal?

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41–50 of 81 posts

Re: Ask HN: Why do they make cars go so fast if it’s illegal?

#41
Generally because machines should serve us instead of telling us what to do. This is an important principle for many of us.

That said I generally stick to the speed limits [1], but what if I need to get to the hospital in a hurry? At least around here local laws are quite clear that you are allowed to break laws and regulations to save lives.

[1]: old habit, wasn't always a well paid programmer and also I mostly think it is the right thing to do :-)

Re: Ask HN: Why do they make cars go so fast if it’s illegal?

#44

Disclaimer: IANAL, but also asked that question once in my youth, and went digging for the answer. They technically don't in a meaningful sense. What they do is make a car that has high torque and can accelerate 0-60 mph as quickly as possible. This has the unwanted side effect of also being able to still continue accelerating quickly past the target zone ( The acceleration in cars are designed around pretty much one…

A bit of a pet-peeve of mine, but it is the power that makes the car accelerate, not torque. With gearing, any value of torque is possible at the wheels, but not for any given speed. A car with 300 Nm of torque but 100 kW of power will never accelerate faster than the same car, but with less Nm and say 150 kW of power. Gearing is suitably chosen according to power production, not torque. The answer to the question "At what RPM will I accelerate the fastest, for a given speed" is always the RPM at which peak power is produced - which may or may not be avaliable because of gearing, but usually you can come pretty close since the power curve is somewhat flat around a region of RPM. Typically.

Re: Ask HN: Why do they make cars go so fast if it’s illegal?

#45
post #32
post #29

Earlier quoted context omitted.

How do you imagine this working for someone who drives across Europe frequently, including sections of unrestricted Autobahn? Or someone who takes their street legal car onto (private) tracks from time to time?

GPS :)

But then you need an up-to-date database of allowed speeds on roads all over the world, and since those already aren't reliable when they're used as indicative data, I don't think that's a viable solution.

It also wouldn't work on road sections with variable speed.

Re: Ask HN: Why do they make cars go so fast if it’s illegal?

#46
What would you make the top speed? When I was a kid the speed limit was 55mph (100kmh). Then they raised it. Some states the speed limit goes up to 75mph, while in others it is 65. There is talk of going faster in some states. (and I might not even be aware of the rules in all states)

Re: Ask HN: Why do they make cars go so fast if it’s illegal?

#47
post #29

Earlier quoted context omitted.

Of course, street-legal automobiles could simply be governed with a top speed of the fastest legal speed limit in a given region.

How do you imagine this working for someone who drives across Europe frequently, including sections of unrestricted Autobahn? Or someone who takes their street legal car onto (private) tracks from time to time?

Limit it to 130 km/h, which is appropriate for almost all or Europe[1]. If you're e.g. in Germany or Poland, you can have it unlocked, but the car stops being road legal anywhere else.

Ideally, they'd just harmonize the speed limit in the EU; a majority in Germany approves of introducing a general speed limit on motorways anyways. But that'd hurt the bottom line of car manufacturers and we can't have that.

Also, GPS-validated speed limits for new cars. And I don't mean just the top speed in a country, I mean the posted speed limit on whatever road you are. Doesn't need to be a hard limit, in case of emergencies and for maneuvering, but make something interesting happen: online registration, enable the hazard lights, I'm sure there are many good options. It's ridiculous we're talking about fully automated driving and we don't even have this simple automation which would get rid of an entire class of everyday offense.

[1] https://de.wikipedia.org/wiki/Datei:Freeway_speed_limits_eur...

Re: Ask HN: Why do they make cars go so fast if it’s illegal?

#48
There are a lot of ways to interpret this question, as shown in by the variety of responses in this thread.

But we could rephrase it to "why aren't top speeds limited to the maximum speed limit?".

It's got me thinking about the creeping culture of safetyism, especially against the current backdrop of Covid-related restrictions.

In some ways it makes no sense that cars are not restricted to a sensible top speed. Either a simple dumb limiter set to the top speed limit for the country, or something more sophisticated using GPS (or a combination of the two). Doing so would possibly (probably?) save many lives per year. Yet it's unlikely to happen because:

1. there's a powerful automotive industry that relies on cars retaining their power as a status symbol

2. there are a lot of powerful and influential people who enjoy driving fast cars.

It frightens me that we are seemingly only able to retain our freedoms when there is some powerful industrial lobby to protect them.

People are currently being subjected to much, much greater restrictions of freedom than having the top speed of their car capped. Entire livelihoods are being destroyed on the basis of "saving lives". Perhaps this is justified. I personally don't think so but a convincing argument can be made.

If there's a conclusion to this, it's that we need to move past the "if it saves some lives, it's worth it" style of argument.

It sounds brutal, but some values are worth holding on to even if they kill people. You may balk at that statement, but you implicitly accept that compromise every day, even if you've never explicitly thought about it.

Re: Ask HN: Why do they make cars go so fast if it’s illegal?

#49

It isn't illegal everywhere. Acceleration is a big part of the enjoyment of fast cars. That's not usually illegal. Also, having better acceleration can help reduce the 'time exposed to danger' when overtaking, which may still be below the local speed limit. Faster cars can be safer, see...

You may be conflating acceleration with velocity?

Acceleration is definitely helpful (to a point , even on the track), but for instance I live in the UK where the max speed limit is 70mph, and my very ordinary car is specced to do more than double that. I don’t see the benefit of being about to do >>100mph outweighing the risks- earlier comment mentions how this arises from the need for useful torque bands in IC engines which explains a lot and makes perfect sense, but with modern engine controllers and especially electric I agree that this is no longer necessary to leave enabled in the vast majority of vehicles.

Re: Ask HN: Why do they make cars go so fast if it’s illegal?

#50
post #45
post #32

Earlier quoted context omitted.

GPS :)

But then you need an up-to-date database of allowed speeds on roads all over the world, and since those already aren't reliable when they're used as indicative data, I don't think that's a viable solution. It also wouldn't work on road sections with variable speed.

Doesn't need to work everywhere for it to be useful. You can always fail fast, literally. The data is available for wide swathes of Europe, for example. Last time I checked it was very accurate even for temporary construction sites.

Variable speed roads, either make the limit the highest speed that's in the range, or come up with a way to communicate the current limit. Most new cars are always connected, anyways. And again, you can fail fast, at least initially. As with all driving aids, the person in the driver's seat bears the ultimate responsibility.

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