Model 3 Energy Consumption Rate, Battery Size, and SC Charge Rates

[JeffK]

126 MPGe equals 3,74 miles per kWh or 3,74 MPkWh
It also equal 267 Wh per mile or 256 WhPM


It is useful in countries where 1kWh costs the same as 1 gallon.

One uses money to pay for those gallons and those kWhs.
What it all boils down to is miles per dollar.

Exactly!

Here's a simple thought... electricity costs me $0.10/kWh and gas costs about $2.20

for 310 miles let's say it's 75 kWh + 10% for losses so that's $8.25 for 310 miles.... so if one says it's for MPG equivalence then 310mi / 126 MPGe * $2.20 = $5.41 That's misleading...
Sooo it'd be cheaper if an EV ran on gasoline?? The EV is more expensive to run than the 126 mpg ICE, which doesn't exist?

It's an apples to oranges comparison at best. They should be picking a national average gas price and a national average electricity price and give consumers a cost per mile or cost per 100 miles if it makes more sense.

I can understand why they've done MPGe for hybrids... but there's no need on a pure EV.

 

[Zoomit]

The 126 MPGe data (267.5 Wh/mi) gives credence to the 237 Wh/mi leak being driving efficiency (battery-to-wall) for the 3LR.

I used 237 Wh/mi to calibrate my driving model for the 3LR and then changed the weight to match the 3SR of 3,549 lb. That results in a driving efficiency of 232 Wh/mi and a usable battery capacity of 51kWh for 220 miles. If we put the 11% charging losses back in, the 3SR might get an EPA combined rating of 129 MPGe (262 Wh/mi).

Again, the only change to the model was the reduced tire resistance forces due to the lower weight car. This does not include any advantage the lighter 3SR will have for non-steady-state driving, so I expect these are conservative and the actual EPA numbers for the 3SR will be slightly better.

As a point of reference, that's only a 2% efficiency gain [128.6/126-1] for a 7% reduction in weight [1-3549/3814].
The i3 22 kWh gains 5.7% efficiency [124.4/117.7-1] over the 33 kWh variant with a 5.5% reduction in weight [1-2799/2961].
The e-Golf 24 kWh gains 2.7% efficiency [118.6/115.5-1] over the 36 kWh variant with a 4.5% reduction in weight [1-3380/3538].

To summarize these 3SR predictions:
Driving efficiency is less than 232 Wh/mi
Usable battery capacity less than 51.1 kWh
EPA combined rating more than 129 MPGe
Wall-to-wheel efficiency less than 262 Wh/mi

All this assumes the 220 and 310 range numbers are the EPA ranges without being "voluntarily lowered", which of course is a big assumption.

 

[Zoomit]

I don't think that is right.

My reference to "battery-to-wheel" was only to emphasize that the charging losses are not included when determining efficiency based on EPA range and the battery's usable capacity.

 

[Zythryn]

Miles per kWh or kWh per mile are great ones for starters.

Ok, how many Miles per kWh does a Honda Accord get?

 

[JeffK]

Ok, how many Miles per kWh does a Honda Accord get?

They don't make a Honda Accord EV to my knowledge.

 

[WarpedOne]

All this assumes the 220 and 310 range numbers are the EPA ranges without being "voluntarily lowered", which of course is a big assumption.

My bet is on Voluntary lowering...
Compare the officially submitted numbers for Model S:

Model S 75:
- charge depleting UDDS - actual distance driven: 333.45 miles
- charge depleting HW - actual distance driven: 342.45 miles

Model S 60:
- charge depleting UDDS - actual distance driven:281 miles
- charge depleting HW - actual distance driven: 291 miles

Model S P90D:
- charge depleting UDDS - actual distance driven: 384.45 miles
- charge depleting HW - actual distance driven: 405.45 miles

Model S 100D:
- charge depleting UDDS - actual distance driven: 449.45 miles
- charge depleting HW - actual distance driven: 455.37 miles
- EPA range: 331 / 337 (335)

With those of Model 3 LR:
- charge depleting UDDS - actual distance driven:495 miles
- charge depleting HW - actual distance driven: 454 miles
- EPA range: 360? / 337? (?)

UDDS is city cyle, HW is highway cycle.
Model 3 LR gets same range on HW as MS100D and about 10% better range in city.
Why would it get only 310 miles combined when 100D gets 335 combined, and M3LR get 10% better in the UDDS. Both are at least the same, M3 potentialy being closer to 350 miles (EPA combined).

 

[MP3Mike]

Ok, how many Miles per kWh does a Honda Accord get?

Going with MPG of 36 that would be 1.06 Miles/kWh.

 

[GSP]

Ok, how many Miles per kWh does a Honda Accord get?

Who cares? Just compate the fuel cost on the window sticker to other cars, gas or electric powered.

Miles per kWh is just as meaningless for a gas car as mpg is for an EV.

It also is better to compare consumption, putting kWh or liters or gallons in the numerator.

GSP

 

[JeffK]

My bet is on Voluntary lowering...
Compare the officially submitted numbers for Model S:

Model S 75:
- charge depleting UDDS - actual distance driven: 333.45 miles
- charge depleting HW - actual distance driven: 342.45 miles

Model S 60:
- charge depleting UDDS - actual distance driven:281 miles
- charge depleting HW - actual distance driven: 291 miles

Model S P90D:
- charge depleting UDDS - actual distance driven: 384.45 miles
- charge depleting HW - actual distance driven: 405.45 miles

Model S 100D:
- charge depleting UDDS - actual distance driven: 449.45 miles
- charge depleting HW - actual distance driven: 455.37 miles
- EPA range: 331 / 337 (335)

With those of Model 3 LR:
- charge depleting UDDS - actual distance driven:495 miles
- charge depleting HW - actual distance driven: 454 miles
- EPA range: 360? / 337? (?)

UDDS is city cyle, HW is highway cycle.
Model 3 LR gets same range on HW as MS100D and about 10% better range in city.
Why would it get only 310 miles combined when 100D gets 335 combined, and M3LR get 10% better in the UDDS. Both are at least the same, M3 potentialy being closer to 350 miles (EPA combined).

And you saw the 78270 wh SOC too right

 

[Zythryn]

They don't make a Honda Accord EV to my knowledge.

Quite correct, so how would you compare the effiency of the two cars?

MPGe allows you to do so, without the need of any calculations or conversions.
It is an easy way to concisely show the relative efficiency of each car.

It is imperative that EVs, hybrids, and gas vehicles have a relative efficiency measurement, for them to succeed in the marketplace.

Going with MPG of 36 that would be 1.06 Miles/kWh.

Excellent, and what did you do to calculate that?
Would you expect that to be as easy for every car shopper to quickly compare gas cars with EVs, than if the conversion were already done for them, as it is with MPGe?

 

[Troy]

Hi. On Reddit, somebody has just posted a link to this document on EPA website. It has lots of data about the "Model 3 RWD Long Range".

https://www3.epa.gov/otaq/datafiles/CSI-HTSLV00.0L13.PDF

 

[JeffK]

Quite correct, so how would you compare the effiency of the two cars?

MPGe allows you to do so, without the need of any calculations or conversions.
It is an easy way to concisely show the relative efficiency of each car.

It is imperative that EVs, hybrids, and gas vehicles have a relative efficiency measurement, for them to succeed in the marketplace.



Excellent, and what did you do to calculate that?
Would you expect that to be as easy for every car shopper to quickly compare gas cars with EVs, than if the conversion were already done for them, as it is with MPGe?

We said $ / mi it works for all vehicles.

 

[JeffK]

Hi. On Reddit, somebody has just posted a link to this document on EPA website. It has lots of data about the "Model 3 Long Range".

https://www3.epa.gov/otaq/datafiles/CSI-HTSLV00.0L13.PDF

There's a thread [Spoiler Alert + Mild Speculation] Tesla has created a monster!

 

[MP3Mike]

Excellent, and what did you do to calculate that?

There is 33.7 kWhs of energy in a gallon of gas. So 36 miles divided by 33.7 kWhs = 1.06 miles/kWh.

 

[Troy]

The data confirms 80 kWh (80.5 kWh to be more precise) for the larger battery because of this calculation:

Total pack capacity = 350 V * 230 Ah= 80,500 Wh = 80.5 kWh

Total Voltage of Battery Packs: 350 Volt (source is page 3 here)
Battery Energy Capacity: 230 Ah (source is page 3 here)

The document doesn't say that 230 is 230 Ah, however, I found another example here from another car that shows the unit for "Battery Energy Capacity" is Ah.

 

[JeffK]

The data confirms 80 kWh (80.5 kWh to be more specific) for the larger battery because of this calculation:

Total pack capacity = 350 V * 230 Ah= 80,500 Wh = 80.5 kWh

Total Voltage of Battery Packs: 350 Volt (source is page 3 here)
Battery Energy Capacity: 230 Ah (source is page 3 here)

The document doesn't say that 230 is 230 Ah, however, I found another example here from another car that shows the unit for "Battery Energy Capacity" is Ah.

Document also says END-SOC - 78270 wh perhaps that's usable capacity?

 

[Troy]

Document also says END-SOC - 78270 wh perhaps that's usable capacity?

Yes, exactly. Usable capacity is 78.3 kWh. It actually says "78270 Wh" at the bottom of page 6 and 7. This is more than the 85 kWh Model S pack's usable capacity. At the time, Tesla was using overly optimistic advertising tactics.

Model S packs, advertised / actual / usable capacity (source for 75, 85, 90 kWh, source for 100 kWh)

• 75 kWh advertised, 75.0 kWh actual, 72.6 kWh usable capacity
  
• 85 kWh advertised, ~81.5 kWh actual, ~77.5 kWh usable capacity
• 90 kWh advertised, ~85.8 kWh actual, 81.8 kWh usable capacity
• 100 kWh advertised, 102.4 kWh actual, 98.4 kWh usable capacity

On page 7 it also shows numbers like 171 Wh/mi efficiency and 454 mi range but I think these should be ignored because they appear to be dyno test scores without counting other factors like air resistance which are added to calculations later on.

 

[Zoomit]

So 78,270 Wh / 237 Wh/mi = 330 miles.

 

[MP3Mike]

The data confirms 80 kWh (80.5 kWh to be more specific) for the larger battery because of this calculation:

So that would mean that the Model 3 Standard range is probably 55 kWh. (Right where we expected it, but I don't think many people thought the LR model would be 80 kWh.)

 

[Zythryn]

We said $ / mi it works for all vehicles.

That already exists on the sticker. Although it isn't exactly $/mi, it lists average annual fuel costs.
Also, cost / mile says nothing about efficiency.
The purpose of MPG and MPGe on the sticker is not to compare fuel costs, it is to compare efficiency.
I have yet to hear a better yardstick than MPGe for that purpose.