The 310 Mile (LR) Model 3 EPA Reported Energy Efficiency

[SageBrush]

Folks just did better than 6 miles per kwh in a models s. Definitely possible if you drive super slow under ideal conditions. This has nothing to do with daily driving of course

My Prius Prime matches up to the Model 3 pretty well at a Cd of 0.24 and mass of 1530 Kg; I presume similar frontal area in the two cars.

When I drive 42 miles to work in EV only I consume 5.6 kWh from the battery. This is aided by:
6000 ft elevation (about 80% of sea level air density)
A 400 meter net drop, worth about 1.5 kWh in potential energy
Speeds of 30 mph for 10 miles
55 mph for 8 miles
63 mph for 24 miles

So on a flat it would work out to 7.1 kWh for 42 miles or 5.9 miles a kWh, albeit with a Cd of 0.192 at sea level. Staying at 55 instead of 63 mph at sea level should ~ give 6 miles a kWh

 

[KarenRei]

I'm very skeptical that it will manage 6 miles/kwh, on any realistic basis as I know what that takes in my Volt.

It won't. These figures are for if you had zero internal losses (battery, drivetrain, parasitic).

 

[malcolm]

Looks like data from a Rolling Road.

Achievable at low speeds, if you can stand the boredom, but unachievable when moving faster through air.

Or maybe they did the test over at Hyperloop One

 

[McRat]

That is not what it says. (Nor would it make any sense for the range to increase while you drive faster).
The y axis is watthr / mile...ie how many watthrs the car uses per mile driven on a flat surface. So, if you are reading 345 watthr at 75mph, then the range would be 78,000/345 (usable energy is reported at 78kilo watt hrs)

DOH! You are right. I made a bonehead graph mistake. Each line on that graph is 20 not 10, and I rounded too much. 323.4 miles at 75 mph from the graph:

1,000 watts / kW x 242 (from graph above @ 75mph) watts-hours per mile = 4.1322 kWh per mile

4.1322 kWh/mi x 78.27 kW (per EPA filing - END-SOC 78270 Wh) = 323.4 miles.

But even then, it would be good news if true, however, that is still way above what the Model 3LR's 310 miles advertised range is, especially at 75 mph.

Honestly, I don't think it is going to happen. Not 10 miles per kWh at 30 mph, nor 4.13 miles per kWh at 75 mph. It could, but it's not likely.

Crossing my fingers, but that's more range than the Model S 100D at 70 mph per Tesla's own advertising but at a higher speed. I doubt they would shoot themselves in the foot. Some buy the 100 for range.

We will see. 310 EPA combined would be good. Anything higher is icing on the cake.

 

[ratsbew]

DOH! You are right. I made a bonehead graph mistake. Each line on that graph is 20 not 10, and I rounded too much. 323.4 miles at 75 mph from the graph:

That would be amazing. I normally drive 65 so the range would be closer to 350 miles. That's exceptional!

 

[SageBrush]

That would be amazing. I normally drive 65 so the range would be closer to 350 miles. That's exceptional!

Just my WAG, but I'd discount the raw range calculation by a good 5% for sure, and perhaps 10%, for on-road results. The EPA discounts them 30% to ~ match the 5 cycle weighted result unless the manufacturer can prove otherwise with actual 5 cycle testing.

 

[shrspeedblade]

Simply the EPA rating on the posted picture of the Monroney sticker of 126 MPGe has me excited- 4.5 miles/kwh is so good that many 500 mile driving days only take 1 supercharger stop and I could drive almost all week and charge only once!

(I know, I know, keep it plugged in because you never know and a plugged in Tesla is a happy Tesla, and two short SC stops may very well be less than one long one.......)

 

[Reciprocity]

DOH! You are right. I made a bonehead graph mistake. Each line on that graph is 20 not 10, and I rounded too much. 323.4 miles at 75 mph from the graph:

1,000 watts / kW x 242 (from graph above @ 75mph) watts-hours per mile = 4.1322 kWh per mile

4.1322 kWh/mi x 78.27 kW (per EPA filing - END-SOC 78270 Wh) = 323.4 miles.

But even then, it would be good news if true, however, that is still way above what the Model 3LR's 310 miles advertised range is, especially at 75 mph.

Honestly, I don't think it is going to happen. Not 10 miles per kWh at 30 mph, nor 4.13 miles per kWh at 75 mph. It could, but it's not likely.

Crossing my fingers, but that's more range than the Model S 100D at 70 mph per Tesla's own advertising but at a higher speed. I doubt they would shoot themselves in the foot. Some buy the 100 for range.

We will see. 310 EPA combined would be good. Anything higher is icing on the cake.

It could also be that the EPA ran the battery to 0. I know in my Model X, I have 10 (or more) miles after it says 0. I have never actually had it die but did go 10 miles on 0 once. Model 3 LR could have 13 mile reserve that is not the anti-brick reserve, but more of a reserve like in a traditional ICE.

 

[stopcrazypp]

It could also be that the EPA ran the battery to 0. I know in my Model X, I have 10 (or more) miles after it says 0. I have never actually had it die but did go 10 miles on 0 once. Model 3 LR could have 13 mile reserve that is not the anti-brick reserve, but more of a reserve like in a traditional ICE.

The way the EPA (or rather the manufacturer, since it's the manufacturer running the test and submitting results to EPA) determines the end of test is when the car can't keep up with the cycle anymore. They don't care what the dash says.

 

[ChadS]

I know in my Model X, I have 10 (or more) miles after it says 0. I have never actually had it die but did go 10 miles on 0 once.

I am sure you had this experience, but it is not because there is a driving reserve past zero. Just to be clear: THERE IS NO DRIVING RESERVE PAST 0.

Tesla has been consistent on this (and it wouldn't make any sense for them to do it anyway). Many owners on these forums have reported running out promptly at 0; a few even ran out slightly before.

The problem is that the battery doesn't store miles. Tesla has to guess when you will run out. They don't want you to run out early, so sometimes the guess is a little conservative. This means you MIGHT be able to go past 0, if you are lucky. But it is only because you are lucky; the car is not designed that way.

 

[SageBrush]

126 MPGe has me excited- 4.5 miles/kwh

How did you calculate 4.5 miles per kWh ?

I get 126/33.4 = 3.77 miles/kWh (from the wall.)
Presuming 12.5% charging losses, 4.3 miles a kWh from the battery

 

[KarenRei]

I'd call designing your range measurement algorithm so that for 95+% of users (from the anecdotes I've been seeing) you have 10-15 mi more after zero "designing in a reserve". But I can also understand why they wouldn't want to call it that. And I agree that it's important to realize that charge measurements are not precise, and you might be unlucky and not even make it to zero.

But odds are - as in most cases - you can go past zero.

 

[shrspeedblade]

How did you calculate 4.5 miles per kWh ?

I get 126/33.4 = 3.77 miles/kWh (from the wall.)
Presuming 12.5% charging losses, 4.3 miles a kWh from the battery

I'm used to the MPGe calculations in my Volt which come out slightly different, so I'm literally using "alternative facts" LOL!

 

[SageBrush]

I'm used to the MPGe calculations in my Volt which come out slightly different, so I'm literally using "alternative facts" LOL!

Oh ... I see.
Perhaps explained by a less efficient EVSE and OBC. I think the Volt setup loses 18% during charging which would indeed calculate out to 4.5 miles a kWh at the battery if the EPA tested the Tesla with same setup.

 

[radami1]

I don't understand the higher math that gives you an 85 kwh battery. My calculation gives about a 70 kwh battery at most. At 65 mph, the consumption is 200 wh/m. That's .2 kwh/m. Range 310m times consumption .2kwh/m gives 62kwh total consumption. Add 8kwh for anti-brick cushion and you get 70 kwh total capacity.

 

[gregincal]

I don't understand the higher math that gives you an 85 kwh battery. My calculation gives about a 70 kwh battery at most. At 65 mph, the consumption is 200 wh/m. That's .2 kwh/m. Range 310m times consumption .2kwh/m gives 62kwh total consumption. Add 8kwh for anti-brick cushion and you get 70 kwh total capacity.

But even if your consumption figure is correct, who says the range will be 310 miles at 65 mph? The 310 miles is for the EPA 5 cycle test.

 

[EV_enthu_jp]

I get 126/33.4 = 3.77 miles/kWh (from the wall.)

You are using wrong parameter, 33.4.
It should be 33.7 kWh/mile.
Miles per gallon gasoline equivalent - Wikipedia

 

[miimura]

I don't think anyone has said it in this thread, so just to be clear, the polynomial in the graph at the start of this thread is only counting the energy required to push the vehicle down the road. This includes the friction of turning the motor and drive shafts, but not the motor efficiency itself. It also doesn't include any ancillary loads like climate control or conversion losses between the HVDC battery and the 12V systems.

 

[SageBrush]

I don't understand the higher math that gives you an 85 kwh battery. My calculation gives about a 70 kwh battery at most. At 65 mph, the consumption is 200 wh/m. That's .2 kwh/m. Range 310m times consumption .2kwh/m gives 62kwh total consumption. Add 8kwh for anti-brick cushion and you get 70 kwh total capacity.

Your error is in thinking that roll-down forces are the only ones considered when the EPA comes up with 310 miles range. The raw range data varies from 450 - 495 miles of range and then gets discounted down to 310 miles to account for higher speeds, A/C use etc.

The EPA CSI report has the raw data