They are doing a programmatic conversion of 1000km to miles, because most Americans don't have a clue about the metric system. What's the problem?
>What else should I not trust in their publication?
I'd love to hear about what you think is "untrustworthy" about converting from kilometres to miles so the audience can visualize the distance. 1000 km = 621 miles, this is a fact.
1000km is not an exact figure. It’s rounded, probably up. Somewhere between 900km and 1100km. Likely closer to 999km than 1099 because they’d want to publish the biggest number they can reasonably claim. So you can assume the real range is between 900km and 999km.
The correct translation to miles would be “600mi”. Because 621 invents precision that wasn’t there in the original figure.
The correct thing to do would be to write the conversion as "1000 km (~621 miles)", so that the original value is not lost.
The former invites you to imagine that the actual Mileage will vary depending on other factors in the car design. The latter suggests some inherent theoretical limit caused by this technology that makes 621 miles into an absolute best case range.
Which of these two do you think the original author of the claim was trying to communicate?
Continuing the thread with rude pedantry is not adding anything useful to the conversation.