This "200+ mph self-driving cars" thing gets repeated a lot on HN but I've never seen anything to suggest that it would be remotely fuel-efficient. There is a r

This "200+ mph self-driving cars" thing gets repeated a lot on HN but I've never seen anything to suggest that it would be remotely fuel-efficient. There is a reason why today's high-speed rail rarely exceeds 200mph / 320km/h, namely that around that value, wind resistance starts to exhibit cubic growth. Even with ultra-dense automated slipstream driving, I can't imagine this being very efficient. Some citations would be greatly appreciated. Tyres might be an even bigger problem. See the Bugatti Veyron: "It uses special Michelin PAX run-flat tyres, designed specifically to accommodate the Veyron's top speed [258mph / 415 km/h], and cost US$25,000 per set. The tyres can be mounted on the wheels only in France, a service which costs US$70,000" from https://en.wikipedia.org/wiki/Bugatti_Veyron https://en.wikipedia.org/wiki/Bugatti_Veyron