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Comment by ssalka | Hacker News Reader

This makes me wonder, why are cars built to go ~120mph in the first place, when I can't think of a single place in the US where it is legal to drive that fast on a public road?

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Because an engine works more efficient if it is not running at its limits. So driving at 90mph with an engine that can go 120mph is more efficient than an engine that can go 90mph.

Depends on the design. Smokey got them past their limits and made them extra efficient: https://www.yellowbullet.com/threads/smokey-yunicks-hot-vapo...

Because a car that does well on the highway is also equipped for higher speeds. You don't want an engine that redlines at highway speeds so it's geared down, but that means you have headroom. You don't want tires or suspension that run at their limits during normal use either, so you get a car with all the parts it needs to go faster.

Cars already have regulators to control top speed. The change would be to set those regulators to something like 80 mph.

It sounds like you're saying the Jeep Eagle wasn't the greatest vehicle of all time. Almost like your saying that pieces of the interior falling off at speeds greater than 55 mph wasn't a good thing. I guess this is just one of those times we will have to agree to disagree.

I think partially it's because you don't want to have your engine/transmission constantly running at their peak. Sure your average car engine these days can probably do 120mph, but it won't do it for very long in terms of the car's overall lifetime.

Many consumer cars aren't. The engine may permit that level of speed, but the rest of the car isn't necessarily built for that. In some lower-end cars even driving at legal highway speeds can be uncomfortable.

A bunch of reasons actually. There are loads of places in the US where it's reasonable and legal-ish to go 80 mph. If you want a nice, affordable car that can go 80 mph without feeling like its about to fall apart, it will probably be able to go 120 mph too.

There are scenarios where I would want a lot of acceleration or top speed (or both), legal consequences be damned. You're not buying a car that goes 120mph all the time, you're buying a car that can do that once if you need it to, even though you very likely will never need it.

But most importantly, because people want it and companies are willing to build it.

The German autobahn also exists and still has sections with no speed limit (for now, anyway). Being "built for the autobahn" (ie high speed) is a major selling point for German cars.

All roads are not public.

The vast, vast majority of cars are designed with public roads in mind. Out of the huge number of people that drive in the US, a very small portion regularly use their cars off public roads where 120mph is a usable speed.

And that's why we already have limiters in them. This article is about exceeding the speed limits, not going over 120MPH.

Private roads are a thing too. Also racetracks.

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