Using the Primes 120v Charger at 240 Volts, Cost $20 !!!

I used the included charger on a 120v 15A outlet in the garage until my wife bought an electric car. Then I had to pull 6 gauge wire allllllll the way across the house and garage to put in her charger, and I had half a roll of 12/2 sitting around, so I figured why not pull a dedicated wire for the Prius at the same time?

It's a 240v, 20A circuit. The little charger that came with the prius works great. It still only pulls 12A, but 12A at 240 is twice as fast as 12A at 120.

So it's not a hypothetical for me. Works fine.

The car would charge a bit faster if I put in a bigger charger, but the one that came with the car is free. Add to this that the included charger puts out 2.8kw and the car maxes at 3.3kw, so you're looking at a really small (500w) reward for upgrading to a bigger charger.

You could even use 14g wire if you plan to stick to the included charger, since it tops out at 12A.

As a note for fuzzy1, please don't google allowable circuit ampacities and read the commercial 90°C THHN column. THHN in conduit is not romex, 90°C is almost 200°F, and I strongly doubt your breaker (which is part of the circuit) is rated for 90°C in the first place. I further guarantee that a structure fire at your house will be more expensive than whatever you were going to save by going down a wire gauge. Continuous loads (like a car charger) can be at most 75% of the ampacity of the circuit that they're on. So on a short run, you'd need 14g wire and 15A breakers for a 12A load, 12g wire and 20A breakers for a 15A load, 6g wire and 50A breakers for a 40A load, etc. (This is also why the included charger pulls 12A max.)