[AdrianB1]

That's exactly the case. Driving from Bucharest to Vatra Dornei, Romania. No highway yet, the one in construction (A7) is still going around the Carpathian mountains for 370km, it will make the drive faster but not shorter. Also driving highway speed takes more gas.

[limitedfrom]

Then argue for convenience/speed/fun as I write here[1], not in the conversation about fuel usage. Even your example, driving from Bucharest to Vatra Dornei, RO is 490 km (DN12; 1.41x) or 520 km (DN2; 1.5x) vs 347 km, hardly 2-3x the parent comment you're responding to, again keeping in mind that the airport won't be in the middle of the city.

As for highway speeds, cars are calibrated to have the highest efficiency at highway speeds[2][3], so per distance, most cars will do best at reasonable highway speeds.

[1] https://news.ycombinator.com/item?id=41166749 [2] https://www.researchgate.net/figure/Speed-fuel-consumption-c... [3] https://qph.cf2.quoracdn.net/main-qimg-2ddbd8f31c84cefba540d...

[yunohn]

> driving highway speed takes more gas

Hmmm, in my experience, highway speeds are conducive to ICE efficiency and use less gas than city traffic stop and go results in. It also disperses pollution outside the areas people work/reside in.

[creshal]

There's three speed categories as far as the EU is concerned:

- highway

- not highway, not city

- city

The 90-110km/h limits of regular roads tends to hit the sweet spot of engines more reliably than the 130+ of highways, a lot of smaller European car engines are uncomfortably close to redlining at 130+, especially older ones.

[sdeframond]

Air resistance is not linear, which makes it difficult to be more efficient at higher speed, even if the engine is tuned for this.

In my personal experience with both my current and previous cars, the sweet spot is constant speed about 65 to 80kph.

It does feel slow though.