[Mustang Mach-E]

Yes, that is from charging to what the car calls 100% down to what the car calls 0%. There is a buffer at the top and bottom ends of the battery, which is why the physical battery is 99kwh but Ford reports it as 88 kwh. The car will never let you drain the battery to absolute 0 because that seriously damages a Li-ion battery, nor truly charge it to 99kwh full because doing so on a regular basis also damages the battery.

For example, when the car reads 100% it probably is holding 93kwh, and when it reads 0% it will likely still contain 5kwh. To protect the battery from damage it won't let you directly charge it or drain it beyond those limits. However, if you leave Li-ion sitting for a long time it will discharge, so you never want to leave it sitting at that low of a level for a prolonged period.

So yes, you only get 270mi range if you take it up to what it reports as 100% and drain it down to what it reports as 0%.

So I am driving a BMW 328d with a 15 gal fuel tank. We average anywhere from 42 - 48 mpg on this vehicle while on the highway, including long road trips. We have on occassion gone 700 miles on one tank full when we knew where the next diesel pump was.