I used to remember closely following tractor trailer trucks to maximize fuel economy back in the ICE days, and a though occurred to me that with the right software tweaks, our Tesla Model S/X autopilot be can really good at this. It was reported that by closely following a truck, one can save 10% energy at 100ft, maybe 40% energy at 10ft when moving at say 90km/h (55mph). Hey, Mythbusted did it, so it must be true right? Want to Save Gas? Follow That Truck! MythBusters (2007 season) - Wikipedia Now, 100 ft is really too close for comfort at highway speeds and 10ft is blatantly unsafe. However, given that a Mode S/X can brake harder than a truck and autopilot reaction time can be a lot better than human, there may exist an auto-draft mode that would follow a large truck at say 50ft and allow the following vehicle to save 20-25% energy, pretty significant. 50ft is about 0.5s at 60mph/100km/h, probably well within reason for autopilot reaction time. Imagine, instead of 200wh/km we would do 150wh/km going at the same speed.