250Wh can move my EV car (Tesla Model Y) 1 mile in around-town traffic (i.e. not at highway speeds).
So to move the car 30 miles, I need 30*250 = 7.5kWh.
If 1kWh costs $.36 at a DCFC, then 7.5kWh of electricity costs $2.70.
Compared to $4.86/gallon and assuming an ICE car gets 30mpg, that says electricity at a DCFC is about 55% of the price of gasoline, for the same number of miles driven.
The breakeven mpg is 30/.55 = 54mpg. (This is a bit different from your figure of 46.6mpg because you were assuming 290Wh/mile and I was using 250Wh/mile.)
I was using 30mpg above because I'm comparing to my ICE sports car which is fun and fast and gets 30mpg. High-mpg ICE cars are (IMHO) less fun. (And my ICE car is still not as fun or fast as my Tesla).
So your numbers are in the right ballpark. $.36 is roughly correct for electricity at Tesla superchargers too (it varies depending on where and when you charge).
But at home where I usually charge I pay $.14/kWh for electricity. If I compare that price with my 30mpg ICE car, we see that I pay $1.05 to move my Tesla 30 miles. Premium fuel (which my turbocharged ICE car requires) is about $4.10 where I live. So for me my cost of energy is 4.10/1.05 = 3.9x. That is, my ICE car costs about 4 times as much to operate as my Tesla. And it's less fun to drive.
Caveat 1: For highway driving, the Tesla requires more than 250Wh per mile because of air resistance at speed, so the price advantage is smaller on the highway. That's even more true if you use superchargers (see above). But Level 2 chargers are common at many hotels and are usually free. So if you take road trips and are not in a hurry, you can avoid DC fast chargers and their high costs. Most hotels do not provide free gas pumps, but many provide free charging for EVs.
Caveat 2: Teslas eat tires like candy. You WILL have to buy new tires more often
with a Tesla than with an ICE car. But that's the only maintenance expense
that's higher with an EV in my experience.
Agreed on all counts, vehicles are a very complicated product segment so specifics will always matter a lot, but overall running costs are usually going to go in favor of the EV assuming you can charge at home or at your destination. Something like a Prius Prime is probably the only type of vehicle that can realistically compete on running costs for the average consumer and it will probably be a lot more boring than any EV other than the Leaf or Bolt.
I do wish we had seen more performance oriented hybrids at reasonable price points since they get the benefits of instant torque without as much of a weight penalty as full EV but I think that we might already be a bit too late into the EV transition for that.
So to move the car 30 miles, I need 30*250 = 7.5kWh.
If 1kWh costs $.36 at a DCFC, then 7.5kWh of electricity costs $2.70.
Compared to $4.86/gallon and assuming an ICE car gets 30mpg, that says electricity at a DCFC is about 55% of the price of gasoline, for the same number of miles driven.
The breakeven mpg is 30/.55 = 54mpg. (This is a bit different from your figure of 46.6mpg because you were assuming 290Wh/mile and I was using 250Wh/mile.)
I was using 30mpg above because I'm comparing to my ICE sports car which is fun and fast and gets 30mpg. High-mpg ICE cars are (IMHO) less fun. (And my ICE car is still not as fun or fast as my Tesla).
So your numbers are in the right ballpark. $.36 is roughly correct for electricity at Tesla superchargers too (it varies depending on where and when you charge).
But at home where I usually charge I pay $.14/kWh for electricity. If I compare that price with my 30mpg ICE car, we see that I pay $1.05 to move my Tesla 30 miles. Premium fuel (which my turbocharged ICE car requires) is about $4.10 where I live. So for me my cost of energy is 4.10/1.05 = 3.9x. That is, my ICE car costs about 4 times as much to operate as my Tesla. And it's less fun to drive.
Caveat 1: For highway driving, the Tesla requires more than 250Wh per mile because of air resistance at speed, so the price advantage is smaller on the highway. That's even more true if you use superchargers (see above). But Level 2 chargers are common at many hotels and are usually free. So if you take road trips and are not in a hurry, you can avoid DC fast chargers and their high costs. Most hotels do not provide free gas pumps, but many provide free charging for EVs.
Caveat 2: Teslas eat tires like candy. You WILL have to buy new tires more often with a Tesla than with an ICE car. But that's the only maintenance expense that's higher with an EV in my experience.