I own a tesla m3 long range dual motor and I believe it's actual range is a lot less than 310 miles. Correct me if I am wrong here. I charge my 3 to 90% or about 279 miles according to the guage. This is pretty much the max tesla suggests charging it even on long trips. Interestingly I get about 262 miles using about 250 watts per mile. Some days due to the weather or terrain I use close to 280 watts per mile which brings down the max range to less than 250 miles. No one I know drives their car to empty on any kind of regular basis. I personally look real hard for a gas station if my tank gets below an eighth of a tank. Even assuming great weather and pretty flat terrain that means 13% of say 260 miles or about 35 miles remaining in the "tank". That leaves about 200-225 miles as the actual driving range.