Dom are these numbers referring to miles per charge?
Yes, I should have clarified. It is basically 'a tank of gas'. The car then has a mpge (miles per gallon equivalent) that is rated around 69 miles per gallon equivalent to a gas car.
What you see with Rivian, is that they appear to have made a choice to underpromise on epa range (Porsche has done similar, with I think stated range of 220 or 240 but often getting 260-280), versus Tesla which ppl say overstates real life range through gaming EPA test by a few percent.
Detail:
So if someone's Durango or that new Jeep thing (I've driven next both, same size or smaller than my car) and they have a range of 400 miles, you would compare dollar by dollar by taking their fill-up cost and multiplying by 0.75. That product compares to my 'tank' cost on an apples-to-apples range basis (of course you have to figure in than around 10% of my charges are high speed, but that is still cheaper than gas).
Rivian's range is a little hard to figure out because they are shifting from the less efficient quad motors (316 down to 274 EPA test depending on tire size) that my car has to more efficient dual motors (I think 331 down to about about 302 with my tires on the low end). And to add confusion, they are coming out with a bigger battery pack that (I think) they say gets 390 range on the duals.
All that said, even though I am supposed to be getting 274 epa range, without trying I have been getting the 280-308 I referred to. And the 280 was a trip to Gore below freezing. I even started driving 'pretty fast' at the last 50 miles before the charger to get the battery as low as possible and had (between miles and range) gotten to the 280 number - again below freezing.
In my personal experience, on the cold side you get pretty much no penalty above 28-32 degrees. At fairly cold and being 'cheap' with heat I had a 7 % penalty, and then just doing whatever I wanted, toasty as a marshmellow, 20-25% hit in the cold. Now keep in mind that 'cold' was like 15-25 degrees. I realize it gets much colder in some of the places we drive.
That said, there are a lot of hacks to increase efficiency in the cold (
TJ): the big one, before a trip, keep your car plugged in, run the heat and the heated surfaces (wheel and seats). This does two things: gets the heat up to retain it for an hour or two and actually warms the battery. When the battery is warm (even in cold weather) it functions just like it would at moderate weather until, of course, due to physics, it gets cold. Practially that means like an hour or two before your range goes down.
On the flip side, if you go for a short 10 minute drive in the cold, you could see 50% less range if you do not preheat and take these states because the battery will be inefficient while it is cold and it sure won't heat up in 10 minutes of driving (there are youtube videos by 'Rivian Dad' and I think Kyle from out of spec on this).
