Disclaimer: IANAL, but also asked that question once in my youth, and went digging for the answer.<p>They technically don't in a meaningful sense.<p>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 <i>also</i> being able to still continue accelerating quickly past the target zone (<= 85mph). Some street legal cars have governors because of how exceptional their acceleration is.<p>The acceleration in cars are designed around pretty much one extra horrible edge case: accelerating up to freeway speeds, up an onramp that is entirely too steep (yet legally designed), from a standstill (ie, gridlock conditions), <i>while also</i> carrying max cargo capacity. Cars <i>must</i> be able to do this to be considered safe by any meaningful definition.<p>Also, there are no laws <i>against</i> going fast. The laws are purely against the law on public roads, as per the posted limit; there are many private racetracks that are completely legal. Not all countries even have limits comparable to America's, so being able to safely go 100+ mph is worth it if you were to, say, drive on the German Autobahn.
There are a lot of ways to interpret this question, as shown in by the variety of responses in this thread.<p>But we could rephrase it to "why aren't top speeds limited to the maximum speed limit?".<p>It's got me thinking about the creeping culture of safetyism, especially against the current backdrop of Covid-related restrictions.<p>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:<p>1. there's a powerful automotive industry that relies on cars retaining their power as a status symbol<p>2. there are a lot of powerful and influential people who enjoy driving fast cars.<p>It frightens me that we are seemingly only able to retain our freedoms when there is some powerful industrial lobby to protect them.<p>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". <i>Perhaps</i> this is justified. I personally don't think so but a convincing argument can be made.<p>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.<p>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.
To sell them to people who want to go fast or want to have the possibility to go fast, but it also used to be for technical reasons.<p>Most cars have a gaz engine and the efficiency of a gaz engine is not linear. To simplify, an engine often has its best efficiency around 2000rpm and can rotate as fast as 6500rpm but it will then waste a lot of energy, mostly in heat. You want the engine to operate at its best efficiency when you drive normally. So you design the gearbox accordingly, to get 2000rpm at 130km/h for example. But the engine can rotate faster, and therefore you can drive faster than the speed limit.<p>You can limit how fast the engines rotates, most engines do have a limit around 6500rpm, but if you limit the rotation speed, the cars will lack a lot of power. The power is the torque of the engine (how strong it can rotate) multiplied by the rotation speed. So limiting the rotation speed is quite a problem. Many people prefer to buy powerful cars. They don't even know about the torque.<p>You could limit how fast the engine rotates once you reach the speed limit, but for a long time this kind of technology was quite complex and expensive. Nowadays, since maybe 25 years, it's totally fine and cheap to do so. Some German brands put an electronic at 250km/h on their fast cars for example.<p>With electric cars it's another story and while most don't go very fast, mine goes up to 150km/h for example, some are fast only to sell them to people who want fast cars.<p>Today we could definitely put a limit at the legal speed limit, based on GPS and map data and for example, but many people would complain and some would buy a car without the limit. I think the only solution is to force all the constructors to do implement a speed limit at the same time.
Tracks, private roads, autobahns, dynos, plenty of places to go fast legally.<p>Not to mention the extra power goes towards faster acceleration, not just top speed. The same force that gets you an extra 10mph top speed also works to get you from from 0-60mph that much faster.
Can't remember where I read this but IIRC it's not a healthy for a machine to constantly run at 100%, hence you make an engine with a peak performance of 200mph which constantly runs at a cosy speed of 100mph.
From May 2022 all new cars (and buses etc) sold in EU will be fitted with "Intelligent speed assistance (ISA)" systems. ISA meaning sign recognition or other means of detecting the legal speed limit, that limits engine power when the limit is exceeded [1, 2].<p>The European Transport Safety Council (ETSC), the body which supports the introduction of ISAs, says the limiters would reduce collisions by 30%, and save around 25,000 lives within 15 years.<p>I think this is a really brave move by the EU, and a great example of use of technology to save human lives. I wonder if these kinds of "unpopular" legislations are rarely be made by local governments filled with politicians up for re-election every four years as it spells doom for chances re-election.<p>1. <a href="https://www.europarl.europa.eu/news/en/press-room/20190410IPR37528/parliament-approves-eu-rules-requiring-life-saving-technologies-in-vehicles" rel="nofollow">https://www.europarl.europa.eu/news/en/press-room/20190410IP...</a><p>2. <a href="https://www.rac.co.uk/drive/news/motoring-news/mandatory-speed-limiters/" rel="nofollow">https://www.rac.co.uk/drive/news/motoring-news/mandatory-spe...</a>
Because it's not illegal to own or sell a car that can go over the speed limit.<p>A speed limiter is a feature that prevents a vehicle from doing something that many potential buyers want it to be able to do. There's absolutely no incentive to build in one that can't be disabled. In contrast, ones that can be optionally enabled are common - my car has such a feature, and I often enable it for sections of road with average speed checks.
Generally because machines should serve us instead of telling us what to do. This is an important principle for many of us.<p>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.<p>[1]: old habit, wasn't always a well paid programmer and also I mostly think it is the right thing to do :-)
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)
I would appreciate having a mode on my car that automatically sets the governor to not exceed the speed limit as found with GPS. I could turn that off if I really need to and otherwise not have to think about the speed limit.
Fast cars are expensive. Germany wants to sell A LOT of expensive cars. But there is a problem: in most countries fast cars are illegal. So how to solve this problem? German carmakers tells about this problem to the German government. German government finds a solution: allow unlimited speed on German highways so we can make fast cars legal - at least in Germany. Now "they make cars go so fast" and they are legal - in Germany. Now rich people order fast, expensive cars - from Germany. Officially they will not drive them too fast in their countries. Buy everybody can imagine, what happens inofficially... they have enough money to pay for the penalties (with the exception of Finland and maybe some other countries, where penalties are percentage of your income).
The speed of cars mostly comes down to how much power they have. The main reason for having more power is not to increase top speed, which is limited by law, but to increase acceleration, which is not.
It's nice to feel high torque. (And high torque is not illegal per se)<p>Driving a car that doesn't accelerate well while hearing a sound like you are hurting your engine is unpleasant, even for passengers.
* Moving slowly onto the freeway is extremely unsafe<p>* Passing someone slowly is extremely unsafe<p>* Sometimes evasive maneuvers require accelerating rather than braking to avoid danger
1) There are different speed limits on different roads. If you put an artificial limit on how fast your car could go, it would still go illegally fast on slower roads.<p>2) Speed limits change. It would be a hassle (understatement of the week) to update every single car.<p>3) As others have said, you can always drive legally on private tracks.
It isn't illegal everywhere.<p>Acceleration is a big part of the enjoyment of fast cars. That's not usually illegal.<p>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...
The most simple answer:<p>Because people are willing to buy them.<p>It also supports typical human behavior. If you're neighbor has a 400hp car, to "one up" them you buy a 500hp car.<p>Childish? Yes. Are adults with childish behavior new to the human race? Not at all :)
I used to think about this a lot when I was younger, because it makes very little sense, and as I became older I realized how many more things make very little sense and I eventually came to realize the bug is low-level and there are a lot of rich and powerful people who do not want it to be fixed, because it allows for them to exploit everybody else.
Why do they make keyboards that can type hate crime? Why do they make cameras that can shoot child porn? This is possibly the worst question I've seen in this site.
I think lot of people here are going to disagree with me but seems to me there's a case for putting limiters on cars.<p>Drivers sometimes hit other vehicles. Airbags go a long way here. Sadly, drivers will often hit less fortunate road users such as pedestrians and cyclists.<p>We already know that pedestrians hit at 30 km/h vs. 50 km/h stand a much better chance to survive. Sadly, cities are rarely designed for 30, and usually more 50+, depending on the city.<p>Changing cities is, well, possible, but also kind of difficult and unpopular. You know what's easier? Making car manufacturers limit cars' speeds in cities.<p>It's not technologically difficult. Lots of new cars already read speed signs. Almost all of them have some sort of GPS component.<p>Geofencing speed limits seems like a pretty easy fix compared to the infrastructure changes of traffic calming (which we should do anyway). You can make it opt-out (and non-trivial enough to do so) so that most new cars on the road have these limits at least in cities.<p>Does this sound crazy? I'd argue it isn't. Consider that E-bikes/E-scooters are limited to 25km/h in a lot of countries. Similar story with small 50cc scooters. In some places rental E-scooters even have geofenced speed limits already, and the Netherlands is considering a similar plan for E-bikes (ones owned by ordinary citizens).