That idea might be too close to charging per kWh to pass muster in many states, unfortunately.
I've never understood this restriction. But in those situations, I suppose the slower charging could essentially be considered a "congestion tax", encouraging drivers to plan their charging for off-peak. This will particularly help for local charging, where people have quite a bit more flexibility when to charge.
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The problem is that option two does not fix the overcrowding. Most of the time we hear about this is during peak demand e.g. holidays.
The only way to have enough Superchargers available at all time is to make people invest in them when they buy the car. Otherwise you have a 4th of July and a dozen Model 3 owners hogging the charging slot paying their $5 for one of the handful long distance trips they make every year.
I disagree. Charging by the minute would greatly reduce the incidence of people trickle-charging to 100%, or cars left plugged in after they're done charging, so the throughput of cars would be much higher. The current unlimited model encourages these inefficient behaviors. E.g., if you need a 20-minute charge but you're stopping for an hour for dinner; most people would now just leave their car plugged in the entire time, trickle-charging all the way up to 90% if not 100%. If you're paying by the minute, you probably wouldn't do this. So sure, there will be somewhat more Model 3's stopping for charges, but the charges would be much quicker; there would be a lot less supercharger abuse and hogging.
Obviously Tesla has the data and statistics for current supercharger use patterns and occupancy, so they're in a better position to gauge how much there would be to be gained by incentivizing proper charging. (I.e.; charge just as much as you need to get where you're going.) I expect my own behavior would be fairly different if I were paying by the minute, and I don't consider myself a supercharger abuser. The current brute-force approach (unlimited un-metered, encouraging longer charging stops and requiring more superchargers to handle the fleet) really goes against Tesla's ethos of efficiency in my view, especially when scaled up to millions of vehicles. It also substantially diminishes the perceived value of the $35k base model car, if pay-as-you-go is not an option, and $2k extra were required for any supercharger access it all.
That said, by all means they should also continue to offer the $2k unlimited model, and/or roll it into the price of higher-trim Model 3's. I think having both choices would give Tesla (and users) the best of all worlds.