> Musk didn’t elaborate on whether someone would need to drive just as slowly to reach 620 miles in 2017. We’d guess that’s not what he had in mind, though.
He is saying that by 2017 he believes Tesla cars will be able to drive 620 miles under normal driving conditions.
Given that 620 miles is roughly triple a Tesla's current everyday range and it's unlikely that battery performance will triple in the next two years, it seems a lot more plausible that he's thinking of extending the current hypermiling techniques -- add a special software mode, tuck in a few extra battery packs around the edges, etc. -- than about some fundamental innovation that would yield 620 miles from typical driving habits. If he really meant the latter, he could have said so, but keeping it vague allows him to make an ambitious-sounding prediction that is, strictly speaking, still pretty straightforward for Tesla engineers to fulfill.