Unfortunately, it cannot become more accurate over time because it cannot predict what your future driving situation is. Just like in gas cars, electric cars mileage varies depending on a number of variables. Imagine if one month you are driving your car and it's 70° out. And then the next day it is 10° out. You get in the car and it will predict that you will have the same mileage you got when it was 70, but with the cold temperatures you will get significantly less distance. The car cannot predict the weather, or whether you're going up and down mountains, or any of the other variables that affect mileage. The estimate of future mileage is based on your recent mileage since you last reset the cumulative mileage gauge.