electric range in practice

Hello! I would like to ask a question to the owners of electric cars. It’s about the range at a distance, if you drive e.g. 250km highway at a distance. The ranges are always uniformly as WLTP values, e.g. with 350km. Supposedly there is within place and max. 50 – 60 kmh also 400km and more in it, what I can understand myself as a PHEV driver. I can also confirm that the range is less when driving faster on the highway etc… Now I have a little bit of the feelers after a compact E-car extended out and have found two models, however, which come from the same group and have the same battery and motor, found. WLTP range is here so about the 330 – 340km, inside place also 400km should be in it. But what makes me wonder: with one of the brands there have already been thanks on the model side a range calculator. As soon as I choose 120, the range goes back to 200km. Even at 110 I would not have the desired value of 250km would be given anyway.