I have seen this issue covered in many threads but I still don't quite understand it. I am looking at purchasing a used P85D with 30,000 miles that has been driven fairly hard and when charged to 100% it shows a range of 250 miles on the display. My question is whether this number, 250, will be the same throughout the life of the car or if it goes down due to battery degradation. What number did these cars have when new? The car has the 21" staggered wheels. I am trying to figure out the % of degradation for the 30,000 miles.