Perhaps this is normal, but I am not sure. I have about 20K miles on the car as of today and charging to 80% gives me 234 miles. Now as I understand the car is rated for about 241 watts/mile. If I am driving rather efficiently I can get about 220 watts/mile however if drive 10 miles at this rate the display saying how many miles I have driven will decrease by more than 10. Since I am driving under 241 watts/mile shouldn't it decrease by less than 10 or am I missing something?