It is interesting to see them up the estimate to 291, 280 even seemed like a stretch to most people, myself included. Also, why don't they publish city/highway numbers like they do for every other gas car?
Based on numbers I have seen the Model Y like the 3 has a 75kWh pack, how much is usable seems to vary depending on source. Lets just say 73kWh.
That means, at 73,000Wh assuming 100% charge, you would have to average 250Wh/m to get that number. Based on everything I have read on the forum and experienced, that is extremely unlikely.
Based on my past ~1500 miles, I average about 300Wh/m which comes out to a max range of about 243 miles. Granted I do push the Go pedal down all the way a few times on each trip.
On trips where I don't and try to be as conservative as possible, it seems the best I can get is about 260-280Wh/m depending on the type of drive (highway vs city), so lets just call it 270Wh/m to split the difference. That leaves you with a range of about 270 miles in ideal conditions, no passengers/extra weight etc...
At my price for electricity .12/KWh, that comes out to $8.76 for a full battery charge to go 270 miles. In the US, its about $2.20 a gallon now, a similar type CUV (BMW X4) gets about 25mpg on average, so would cost $24.76 to go the same distance.
So the 291 miles number just seems wildly off to me.
With all of that said, this also applies to gas powered cars too, you push the gas pedal more, you get lower mpg. You add weight, you get less MPG. Car companies and EPA estimates are all really based on absolute best conditions, no extra weight, slower speeds etc... I never hit the MPG estimates on my gas cars, just like I never hit the range on my Tesla... Just keep that in mind.
