> force of drag grows exponentially with speed

No, it grows only polynomially [1].

[1] https://en.wikipedia.org/wiki/Drag_equation

You're right. Though, it doesn't really take away from my underlying point.

More specifically, it grows quadratically.

As a German, I love how you call 75mph speeding. There is a huge discussion going on in Germany of introducing a 80mph speed limit on the highway and many people claim that that does not work for them as they regularly drive 100mph average.

> they regularly drive 100mph average

You don't drive 100mph average on German motorways. Especially with the trucks not giving a damn and forcing themselves through to the left lane to pass their colleagues driving 2 kph slower, arriving traffic be damned.

The reality of driving in Germany is that a lot of federal states have maximum speeds on the highway now. And thanks to years of neglect there is a lot of road construction everywhere in the country which means reduced speeds. Speeds are also reduced around cities, around major junctions. And that's usually also where the traffic jams are.

A journey from Berlin to my parents in the Netherlands (525km) would probably take me at least 6 hours normally. That's including stops for lunch, bathroom, fueling, etc. That averages out to about 80-90 km/hour. Only about a fifth or less of the distance allows for driving faster than 130km/h; and usually not for more than 10-20km before you have to slow down for some reason. Driving fast is fun but also stressful because there is always a jerk with a faster car behind you flashing their lights because you are "only" doing 160km/h (100 miles per hour). And high speeds also means accidents are fatal, fairly frequent, and typically result in very long traffic jams.

My experience driving around in different countries in Europe is that you don't get to your destination faster in Germany. Probably France is the most efficient to cover long distances. They have nice, good quality toll roads and you can maintain an average of 120-130 there on long stretches. Spain is pretty decent as well. Roads in Germany are garbage in comparison. There's a reason people are complaining about the state of infrastructure here.

I don't actually own a car and rent cars. Usually, I prefer taking the train, which is not a high speed train even but does that same journey in a bit under four hours. Cheaper, more comfortable, and I can take a nap/relax a bit. Sadly, rail infrastructure is also not in a great state here.

It's a norm to drive 160km/h in Poland. Pretty much everywhere on the A/S roads: https://ssc.siskom.waw.pl/.

Sounds like you'd be in favour of tolls for german Autobahns. Otherwise, perfect comment, so some clueless about german roads might now be scared off and thus not further crowd them.

Depends on time, weekday and which highway. But in general you are correct, which doesn't stop people from claiming that they do and that a 130kph speed limit would be horrible.

Gp didn't call it speeding though. Interstates in the US often do have an 80mph limit, which is in turn routinely exceeded. That doesn't change the fact that 80mph is vastly less fuel efficient than 50mph, which is a typical speed for a two lane highway. Americans (and Germans?) simply don't want to acknowledge that speed kills efficiency, just as incessant speed changes kill efficiency, although the latter is mitigated by regenerative braking.

I'm sorry but this is a pet peeve of mine: drag force does not scale exponentially with velocity, it scales with the square of velocity. Your point stands, of course.

Yes, you’re right.

I’ve gotten use to saying this incorrectly because most people aren’t trained on (or at least don’t remember) the difference between various types of growth functions. Exponential registers much more clearly in everyday conversation.

I also use the word exponential to refer to any curve that trends upwards