We have a long range model 3 and occasionally need to charge it via a Tesla supercharger. We primarily charge it at home. Now a Model 3 is purported to have an eMPG in the 100s. We have been noting on average a charge of $1.00 per a 10 miles of added range via a Tesla Supercharger. For example, our last charge added about 100 miles (of range) at a cost of $10.21. If you assume the cost of a gallon of gas of $3.20 ($/g), I could have purchased about 3.2 gallons of gas ($10.21/$3.20 $/g). Now that equals about 31.25 MPG (100 miles of range added / 3.2 gallons). That is three times less than the quoted 100 eMPG of a model 3! Could other please share their experience and costs - miles versus $. Thank you.
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MPG equivalent using Tesla supercharger is very low
- Thread starter mwresq
- Start date
AlanSubie4Life
Efficiency Obsessed Member
That’s not the definition of MPGe (for better or for worse...). The MPGe number is calculated based on the value of 33.7kWh per gallon of gasoline. It also is a walls to wheels number, so actually when using a Supercharger you will be exceeding the rated MPGe (assuming your driving conditions are conducive to meeting the rates range), because Tesla is taking the hit on the AC-DC conversion losses.
Unfortunately, Superchargers have to be expensive, in order for Tesla to not lose money on them! Fortunately, they are only ever used on road trips and unusual situations.
Unfortunately, Superchargers have to be expensive, in order for Tesla to not lose money on them! Fortunately, they are only ever used on road trips and unusual situations.
The rating is MPGe. Miles per gallon equivalent. It's an _energy_ equivalence, not a cost equivalence, reflecting relative efficiency of the vehicle at using energy.
You charge at home, which is what makes EVs normally much cheaper to fuel, as the cost of home charging is lower than the cost of public charging.
It should be noted that relatively speaking Tesla's price is for fast charging is lower than other charging companies.
In the longer term, at higher volumes, charging prices should come down a bit, as public chargers see higher overall use.
Electricity pricing is normally such that high power users pay a demand charge based on peak, which makes low-use chargers have poor economics, but high-use chargers much better.
You charge at home, which is what makes EVs normally much cheaper to fuel, as the cost of home charging is lower than the cost of public charging.
It should be noted that relatively speaking Tesla's price is for fast charging is lower than other charging companies.
In the longer term, at higher volumes, charging prices should come down a bit, as public chargers see higher overall use.
Electricity pricing is normally such that high power users pay a demand charge based on peak, which makes low-use chargers have poor economics, but high-use chargers much better.
DopeGhoti
Active Member
$1.00 per 10 miles of range? Last time I used a supercharger, I added 200 miles of range for $6.
Evan1701
Member
When I got my M3 about a month ago, I used the supercharger in Lexington, VA and it cost me $8.00 for 150 miles of range. Your mileage may vary... literally!
JohnSnowNW
Active Member
I just came to point out that the absolute cheapest gas in San Diego right now is $3.40...and the average is higher. A comparable car to your Model 3 would most likely be running Premium, which is around $3.80.
Actually, Tesla has said they don't make money on the Superchargers. They're expensive so people won't use them as their primary way to charge up and only use them for trips. This is unlike gas stations along highways, which upcharge based on greed.
thefortunes
Active Member
Agreed. I've never paid much more than $10 for effectively a full charge.
But eMPG isn't based on Supercharger pricing. It's based on standard electricity costs
thefortunes
Active Member
Nope. As stated upthread it's based on energy equivalence (33.7 kWh vs 1 gallon of gas) and has nothing to do with cost.
ucmndd
Well-Known Member
As others have rightly pointed out, the units you’re referring to don’t mean what you think they do.
A gas car gets 25mpg whether gas costs $2/gal or $4/gal.
Just like your Tesla gets ~100 MPGe whether electricity costs $0.10/kWh or $0.50/kWh.
A gas car gets 25mpg whether gas costs $2/gal or $4/gal.
Just like your Tesla gets ~100 MPGe whether electricity costs $0.10/kWh or $0.50/kWh.
Skotty
2014 S P85 | 2023 F-150L
The ops question is valid (while talking about MPG and MPGe, the primary inquiry seems related specifically to cost). IIRC, in most places they have to charge by unit time instead of by kW for regulatory reasons. Therefore, it's going to cost more if your charging rate is low. For both your own time and cost of supercharging, try to only supercharge when battery is well conditioned and very low on charge so that you will maximize the charge rate and thus minimize the cost.
AlanSubie4Life
Efficiency Obsessed Member
Yes, as I said, so they don't lose money on them, they charge a lot more than they used to...which is completely fine as it's still cheaper (even when including road trips) than the typical gasoline car - though definitely not as cheap as a Prius! Charging only at Superchargers is generally on par cost-wise when comparing to typical cars (but depends on where you live).
Getting back to answering the question:
I have 11,500 miles on my Nov 2018 Performance Model 3
Local Supercharging visits: 2, for novelty purposes only - left after a few minutes each time, since I could not tolerate waiting for the car to charge.
Supercharging costs: $0
Electricity costs: -$2550 (three electric cars, carbon credit craziness, gravy train is now done, plus solar)
Free work charging.
So 11500 miles, zero to negative cost.
If I had had to pay for electricity, I would be on the ~$0.10/kWh overnight plan, and my costs would have been about 11500mi * 285Wh/mi * 1.25 * $0.1/kWh = $410 (3.6 cents/mi)
However, you would have to add to this some fixed monthly cost for being on that plan (it would effectively be $6/month I think since I do typically barely satisfy the minimum bill), plus some extra money to run AC in the summer at a higher rate (~$0.46/kWh) than my current rate (~$0.26/kWh).
My MPGe was about: 33.7kWh/galE / (285Wh/mi*1.25) = 94.6MPGe
Last edited:
Apparently this EPA rating that I thought came from the EPA really comes from each automotive manufacture. Appears that Ford may had fudged their numbers. This proves to me that the government is not really doing any vehicle EPA testing after all. So lame.
https://www.cnet.com/roadshow/news/ford-mileage-lawsuit-ranger-f150/
https://www.cnet.com/roadshow/news/ford-mileage-lawsuit-ranger-f150/
The MPGe calculation assumes something like 12c/kWh, the national average. The supercharger is over double that, so, the comparable MPGe for the SC is going to be less than half.
nwdiver
Well-Known Member
.... the MPGe calculation assumes 33.7kWh per gallon ( 'e' is for Equivalent) and a Model 3 can go ~120-ish miles depending on the configuration. That's it. ~120 miles per 33.7kWh of energy. ~120mpge. $ isn't part of it...
AlanSubie4Life
Efficiency Obsessed Member
No, it assumes 33.7kWh/gal. If you want to try to convert that to a price equivalent to the national gas price average....that 12c/kWh would be $4.04/gal for the national average which is definitely way too high.
This is not an accurate statement.
Just like MPG has no cost component, the MPGe also has no cost component.
For reference, please read
Text Version of the Electric Vehicle Label | US EPA
seattlite2004
Active Member
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