Edmunds did a somewhat loose, but interesting test with various EVs and found that the Taycan's official EPA range is an incredible underestimate and much more so than other vehicles some of which seem to be overestimates in real range vs EPA range
https://www.edmunds.com/car-news/ele...s-edmunds.html
It's not like the companies are lying about things--the EPA tests are what they are, but it's important to note that EPA has two different tests you can submit to, one a two cycle and one a five cycle test, and that carmakers can voluntarily lower their rated range. I feel like that's kind of silly for comparison's sake though. It should be one test that is always conducted and always known.