Post by Peter Trei Post by J. Clarke
On Tue, 12 May 2020 07:15:26 -0700 (PDT), Quadibloc
Post by Quadibloc
??? Right now the people who produce the stuff based on putrid
dinosaurs are paying people to take it. I don't think that Tesla can
get operating costs lower than that.
It is true that, for a brief moment, the price of oil went negative on the futures
market for certain dates. That, however, has since been corrected. Filling the
tank of one's car still costs money.
So does charging one's electric.
Right, now, my Tesla is roughly the same cost per mile as an
equivalent Dinosaur car
(BMW 328i) on the highway, and a good deal cheaper in the city. That's with expensive
New England electricity and currently cheap gas.
If you want to run the numbers, highway uses about 240 Wh per mile, and 160 in town.
Huh, I would have thought that those numbers would be equivalent. I
guess that Tesla's regenerative braking must be awesome.
There is very little evidence that you do much thinking.
Or else you are driving 150 mph on the highway.
Hey! Here's a few THOUGHTS for you:
What don't you do very much on the highway?
What DO you do?
Go a lot faster than you do on city streets!
What does going a lot faster do to the air resistance and thus power
required in order to DO it?
It increases it! Air resistance rises as the square of the increase in
speed, and power required rises as cube of the increase.
There is also mechanical resistance that muddies the waters, but to put
it simply (for you):
When you go from driving 30mph to 60mph, you're fuel consumption will
increase by EIGHT TIMES.
Now, there is another factor which means you don't notice this:
When you're driving in the city, you don't drive at a constant 30mph.
You move away from a stop, get up to speed, then slow down and turn all
that kinetic energy you've expended fuel to acquire into heat in the
braking systems. That effect masks how much more efficient the basic
operation of a vehicle at 30 as opposed to 60 really is.
But here's your last thought for this post:
Does an electric car throw away all of the kinetic energy you've put
into it every time you slow down or stop?
It takes that kinetic energy and recaptures a lot of it by turning its
drive motors into generators!
The precise reason the figures are only different by a factor of 1.5 is
that the regenerative system ISN'T awesome, and (as I already said)
mechanical losses even the difference out somewhat as well.
You could have figured all of this out on your own...
...if you had actually thought about it.