How are miles calculated on Superchargers

[IraSch]

I'm confused about how the Superchargers figure out miles. I just filled up using free (referral) supercharger miles. On the screen when it was done, it said 177 miles added. When I checked my Loot screen, I see that I was charged for 110 miles against my free credit. Between fill-ups I actually traveled 113 miles according to the odometer.

I was running with 4 people and using a lot of AC, so the difference between 177 "EPA" miles and 113 actual miles is easily explained.

Certainly not complaining, just trying to figure out how it works.

And when it comes time to start paying for supercharger fill-ups, am I charged per KWh or mile?

Thanks.

 

[swaltner]

And when it comes time to start paying for supercharger fill-ups, am I charged per KWh or mile?

Supercharger Support

Learn more about Tesla Superchargers, including best practices, charging rates, payment methods and locating a Supercharger when you're on the road.

www.tesla.com

While Tesla grants Supercharger rewards as a specific number of miles, you never pay for Supercharging per mile. You are either billed by the kWh or by the minute. The answer to this question is dependent upon which State (ie: New Jersey vs Kansas) the Supercharger is located. In most places, you are charged by the kWh. In some states, something like 1/3 of them, you are billed per minute. Kansas is one such state. The reason for this is that Kansas and these other states have laws that only allow utility companies to charge customers per kWh for electricity. I believe the underlying logic is that if you're billing per kWh, you want certification on how they measure that energy, similar to how the pumps at gas stations need to be certified to verify they properly measure the amount of gasoline delivered. Because of those laws, Tesla charges per minute, with two tiers of pricing - one for above 60 kW and one for at or below 60 kW. The pricing of a specific Supercharger location is given on the map in your car if you select the Supercharger location.

Some people prefer the per-kWh pricing, but I have found the per-minute pricing is MUCH CHEAPER - probably half - if you charge like I do and only charge enough to make it to the "next" station on a trip. On my Model 3 with 300 miles of rated range currently, I'm usually disconnecting from the Supercharger somewhere between 150-200 miles of range on the battery. Charging sessions billed per minute tend to be between $3 and $5, while the same billed per kWh tend to be $6 to $10.

 

[IraSch]

Thanks for the details. I'm in NJ so I guess it is per KWh - would be interested in knowing for sure. I can see where per-minute would be cheaper, especially when only topping off to 80% or so. Initial charge rate seems very high (over 170KWh on the above session at a 250KWh charger), but tapers off significantly toward the end (down below 70KWh).

 

[airborne spoon]

177 EPA miles is the same as 117 rated miles pretty much. Also if you have the car set to mileage instead of percent then at least make sure it is set to rated not ideal.