Here are some real world range tests versus EPA test cycle numbers. Some EVs outperform their EPA range, some underperform it. +\- 5% is about right, but some EVs are a lot better and some are a lot worse:

https://insideevs.com/reviews/443791/ev-range-test-results/

https://www.caranddriver.com/news/a43657072/evs-fall-short-e...

Real world highway range is the best number to look at because it's the worst case scenario for BEVs in everyday driving. Cold weather and performance driving will also shorten the range.