Charging speeds at Tesla’s Supercharger stations vary quite a bit, based on a number of different factors — others sharing the circuit, temperature, overall electricity demand, etc. — with the current level moving up and down in response to these factors as well as others.
Tesla is clearly working to increase the level of current that can be provided, and thus the charging speed, but there are some significant barriers to overcome (overheating, etc.).
On that subject, though, a commentator on the Tesla Motors Club forum by the name of “JPUConn” recently speculated about the company possibly testing out higher-power Supercharging. It’s hard to tell if there’s anything to the speculation, though, or simply wishful thinking.
Here’s the full comment: “Plugged in for a quick juice up at West Hartford CT supercharger and immediately got to 341 mph / 103 kWh with AC on. After a few minutes it dropped to the usual 90 kWh I get at this location. I’ve charged at this location a handful of times with similar conditions and battery level and never been over ~90 kWh. Is tesla testing out ramping up the supercharger speed?”
The “kWh” referred to above are of course actually kW.
A followup comment by “EVie’sDad” provided some further information (that’s possibly relevant): “I got 370 mi/hr charge on Monday in Napa, no one else was there and that is the highest i have seen, but it was about 6:30pm PST in about 87 degree weather, we did have the AC going but on very low, with Range mode on and about 90 miles remaining in the battery. I have seen between 182 and 370 mi/hr, but more commonly between 240 and 340 mi/hr charging, which then begins to ramp down as it gets closer to topping off.”
He also wrote: “Values seen by me in Napa were 373 mi/hr, 293 A, and 370 V.”
Tesla definitely is working to improve charging speeds on the network, but it’s hard to know just from these statements if improvements were recently implemented or if people are just hopeful after seeing some abnormally high numbers.