Electrek isn’t the best resource, but the original information is from like an 1-hour 40-minute Youtube video (as well as a 5+ hour livestream test of the Cybertruck’s range). Link in the Electrek article.
The 254 mile highway range test is perhaps the most troubling issue brought up so far, and even pro-Tesla outlets like Electrek is bringing it up as an issue.
My escooter does 40 miles when it’s 70+ outside but will only get 25-30 in the 30-40 degree range. That said, the Cyber Truck looks stupid and does a shitty job as a truck.