I had an opportunity a couple days ago to run out of gas safely, within EV limp mode of several stations. Went 45 miles below zero range and as it was getting dark, gave up (ran sport mode last 10 miles to hurry the process). Still have valuable information, filled up my 11.9 gallon rated tank to 12.7 gallons! In the past year, I have three times filled up at around zero range to exactly 11.9 gallons, but I wanted to know what my reserve really was. 8/10 of a gallon (minimum) is the answer! But that must be close to the maximum.
Useful information for those who top off and want to know if it is safe to bypass the expensive stations when running close to empty. Fewer fill ups are a luxury. Take your average actual mpg and multiply by .8 to get your true reserve when range remaining is zero. For me, 40 miles is safe. I've already got a real 45 miles in 40 degree weather. For those with 18" tires and/or a brisk driving style, perhaps 25 miles is a good estimate.
Useful information for those who top off and want to know if it is safe to bypass the expensive stations when running close to empty. Fewer fill ups are a luxury. Take your average actual mpg and multiply by .8 to get your true reserve when range remaining is zero. For me, 40 miles is safe. I've already got a real 45 miles in 40 degree weather. For those with 18" tires and/or a brisk driving style, perhaps 25 miles is a good estimate.