That's because the GOM (guess-o-meter) is calculated by the car based on your driving history, depending on carmaker rules: some estimate range based on the last trip, others average just the last 50 kms.
These aren't good methods, because they are not error-proof.
For example, if your last trip was uphill, available range will be calculated as if the world would be completely uphill. At the opposite, if your last trip was downhill, available range of the car will be way too optimistic, because the world is made of up and downhills.
What is the solution? Power Cruise Control® calculates every trip, every time, with up-to-date data (orography, temperature, battery health, ...) starting always from the available energy, not the available range.
Using this approach, we are able to predict, with high accuracy, the energy consumption for a trip, allowing the driver to fully use his battery at its best: no energy surprises will occur, thanks to PCC reliable calculation method.
Do you see now why an electric vehicle should be driven with Power Cruise Control® ?
To solve, every time, every range problem.