DougWantsALeaf wrote: ↑
Thu Mar 11, 2021 7:14 am
I have decided that a rated mile is just Tesla's version of a GID.
It isn't widely understood, to put it mildly, but Tesla's EPA Rated Miles (RM) is actually a fuel gauge
. It is not, and was not intended to be, an estimate of how far the car can go. Rather, RM is the current SOC (Wh) of the battery times the EPA rated efficiency of the car, in miles/Wh. The only way one would get the displayed RM in range would be to drive at precisely the EPA rated efficiency of the car, which, of course, rarely happens.
Since this concept is confusing to Tesla newcomers, many of us recommend changing the display to %SOC and ignoring RM entirely. (It helps that Tesla navigation displays the real time estimate of %SOC at the selected destination in percent, not RM, so displaying RM isn't really useful anyway.)
At high freeway speeds the car uses more energy per mile than EPA rated efficiency. At lower speeds the car will use less energy than than EPA rated efficiency.
My S-60 is rated at 300 Wh/mile (= 3.33 miles/kWh) — yes, that's a lot
worse than a Model 3! — and over the last 57,000 miles I have averaged about 270 Wh/mile (3.70 miles/kWh), despite tens of thousands of miles of freeway travel on road trips and living in a four seasons climate for local driving. So, on average, I beat the EPA rated efficiency quite handily, FWIW.