More excellent efficiency to report

[fluxemag]

I used to get around 325Wh/mi on my S40, and I'm averaging 280Wh/mi on the 3 after 2000 miles. I am definitely not trying to be efficient, so that's still a positive result.

 

[xav-]

Are we reading the numbers off the screen or calculating actual consumption?

If you just read some of the numbers off the screen, then that’s not the full picture, as encouraging as these numbers are - especially relative to the S/X.

If one of you would try the following, it would be helpful:

Charge to a percentage. Let’s call it 90%. Without charging in the interim, please drive over the course of a few commuting days until the charge equals a lower number. Say 20%.

Note miles driven since last charge. Perhaps that number is 120 miles.

Now here’s the fun part, for which you’ll need to know how many rated miles you get at 100%:

90%-20% = 70%.
Miles driven = 120.

Divide miles driven by percentage used to get estimates range from a full charge:

120/0.70 = 171.4 miles

Divide that by your full charge rated range (I’ll use 283 miles as that’s my current max, down from 294 a year ago when I picked up the car from the factory)

171.4/283 = 60.6%

Call that a 40% range hit from the effect of short in-town trips with HVAC and hills and such.

Your efficiency in a Model 3 should be better. My question is how much.

For bonus points, calculate relative MPG. For this, you’ll need the size of your battery in kW, current price per kW and the current price of a gallon of gas in your ‘hood:

I have an S90D. Without getting into the discussion of usable kW, lets just call the pack size 90kW for the sake of round numbers.

From the above, 70% of a full charge got me 120 miles.

70% of 90kW = 63kW.

63kW * $0.26 = $16.38 - what I’d pay with a Model 3 at a CA SC.

Current price of premium gas at Costco (which is what my last ICE required in the dark days B.T.) = $3.64 *twitch*

$16.38/$3.64 = 4.5 gallons

120 miles / 4.5 gallons = 27 MPG.

So... still better than what my last ICE got in town - for trips under 5 miles before the engine components fully warmed up, 17 MPG was the norm. But not as good as a decent hybrid. I don’t like hybrids* but that’s neither here nor there.

Well, there ya go. Hope that helps, especially if you’re non-garaged and want to budget realistically your credit card impact each month from the SCs.

Again, the Model 3 should be better than the above numerical example.

* Nope - don’t like ‘em at all. Pick a side, ffs.

P.S. Seen the April numbers for Model 3 impact upon the medium-sized car segment? *Very* encouraging and most of the competition gets worse city mileage as well.

I wish everyone could follow your advice. I too find those watts per mile numbers very misleading. I will have to redo my math with your numbers but I will drive around 180 miles charging from 90 percent to 20 percent. Watts per mile avg will show as “267 w/h”.

I did not notice similar behavior with the S or even my volt where my advertised range is easily achievable

It seems that a potential culprit is high number of small trips

 

[xav-]

I used to get around 325Wh/mi on my S40, and I'm averaging 280Wh/mi on the 3 after 2000 miles. I am definitely not trying to be efficient, so that's still a positive result.

But how much range do you actually get though?

 

[GoneCrazy]

But how much range do you actually get though?

I don't think the wh/mi numbers are misleading at all. If you're doing lower than 232 wh/mi (assuming 72 usable kwh) you're getting more range than your original charge estimated, and if it's higher than 232 you will get less range that the original charge estimate by a fairly easily calculable amount.

The most misleading number of anything is your actual range left since it is shown in miles. Even then, you can just do a quick addition of your miles driven since last charge to your remaining miles left and determine how much more or less efficient you're driving and extrapolate to when you need to recharge.

 

[chibi_kurochan]

I don't have a Model 3 to report yet, but to my surprise my Prime gets some of its best fuel economy of the year in our summers that skirt 100F. I've presumed that it means the benefit from higher temperatures outweighs the A/C cost, at least in a non-humid climate.

One little funny note about temperature, i charged my 3 to 80% yesterday in the morning. Temp was around low 20C (<68F). Car was asleep at work and temp was around 25-27C (80F) when i left work, i found the car at 81%

 

[jsmay311]

"w/h" (watts per hour?)
"w/mi" (watts per mile?)
"kh/m" (kilohours per meter?)

The units being used by some here is enough to make a high school physics teacher's head explode. (Jk)

 

[scaesare]

I used to get around 325Wh/mi on my S40, and I'm averaging 280Wh/mi on the 3 after 2000 miles. I am definitely not trying to be efficient, so that's still a positive result.

I just wanted to reply to say "Hi" to one of the 3 folks who actually had an S40, and congratulate you on your 3.

 

[pfosse]

Now that the weather in New England is finally starting to warm up, I wanted to revisit my efficiency numbers I'm getting on my ~80mi commute. These are car readings, so they do not take into account charging losses.

Morning commute clocked in at 168Wh/mi. Ambient temperature was 50F. Used heated seats but not HVAC heat. This route has a slight net loss in elevation.
View media item 118287
And here is the overall consumption for the round trip: 184kW/mi. Ambient temperature was 70F. HVAC fan was running but no A/C use. The return trip has a slight net gain in elevation.
View media item 118288

Now that the weather in New England is finally starting to warm up, I wanted to revisit my efficiency numbers I'm getting on my ~80mi commute. These are car readings, so they do not take into account charging losses.

Morning commute clocked in at 168Wh/mi. Ambient temperature was 50F. Used heated seats but not HVAC heat. This route has a slight net loss in elevation.
View media item 118287
And here is the overall consumption for the round trip: 184kW/mi. Ambient temperature was 70F. HVAC fan was running but no A/C use. The return trip has a slight net gain in elevation.
View media item 118288
Most of this drive is on the interstate with moderate traffic and EAP engaged.

Overall, I'm very happy with these results. Using 14kWh for a ~80mi commute is really awesome. It's around 5.5 miles per kWh. My rated range dropped 64 miles for this drive.

What are other people seeing? Is this consistent with your commutes?

With time of day electric pricing, you could get to a penny a mile!

 

[geometro]

Now that the weather in New England is finally starting to warm up, I wanted to revisit my efficiency numbers I'm getting on my ~80mi commute. These are car readings, so they do not take into account charging losses.

Morning commute clocked in at 168Wh/mi. Ambient temperature was 50F. Used heated seats but not HVAC heat. This route has a slight net loss in elevation.
View media item 118287
And here is the overall consumption for the round trip: 184kW/mi. Ambient temperature was 70F. HVAC fan was running but no A/C use. The return trip has a slight net gain in elevation.
View media item 118288
Most of this drive is on the interstate with moderate traffic and EAP engaged.

Overall, I'm very happy with these results. Using 14kWh for a ~80mi commute is really awesome. It's around 5.5 miles per kWh. My rated range dropped 64 miles for this drive.

What are other people seeing? Is this consistent with your commutes?

Just for clarification, it took 82 minutes to go 33 miles... so you are traveling below 30mph on that leg of the commute?

 

[fluxemag]

But how much range do you actually get though?

Certainly not the 310 miles displayed on the screen for full charge. I drove 120 miles straight a few weeks ago and it used 140 miles of rated range at 250Wh/mi. I'm sure it's been mentioned before on this site, but I don't know what Wh/mi you have to hit to get the rated range.

 

[SageBrush]

deleted

 

[D-egg-O]

and....Lifetime is 252 Wh/mile.

Can't stop giving test rides to coworkers, which means stomping on the pedal is unavoidable.

 

[Electroman]

but I don't know what Wh/mi you have to hit to get the rated range.

I would like to know that too.

But looking at your numbers of 120 traveled and consumed 140miles at 250 wh/mile makes me think you need to be at 214 wh/mile to get the rated range. But that seems a bit too low wh/mile.

If you look at 72kWh as the full usable capacity with 310 miles as the full range then it is 232 wh/mile which seems more reasonable.

In the 'S' there is a line in the graph which tells you the rated wh/mile to hit the rated range. I miss that graph in M3

 

[chibi_kurochan]

I would like to know that too.

But looking at your numbers of 120 traveled and consumed 140miles at 250 wh/mile makes me think you need to be at 214 wh/mile to get the rated range. But that seems a bit too low wh/mile.

If you look at 72kWh as the full usable capacity with 310 miles as the full range then it is 232 wh/mile which seems more reasonable.

In the 'S' there is a line in the graph which tells you the rated wh/mile to hit the rated range. I miss that graph in M3

Agree, the trip consumption graph for the past 30 miles and also the power meter instead of the useless bar graph (shows acceleration and regen) on the M3.

 

[nvx1977]

Latest efficiency as reported by the car. This is 2 miles short of a round trip. The total distance is one round trip of my daily commute, which is mostly on an interstate with moderate traffic, plus a day of driving around town. Temps in the low 70s, no HVAC usage. No rain.

5.7 miles per kWh

 

[nvx1977]

Just for clarification, it took 82 minutes to go 33 miles... so you are traveling below 30mph on that leg of the commute?

Awful commute, huh? That's me trying to get to Boston in the morning from southern New Hampshire via I-93. First part of the commute is fairly fast - lots of 70mph travel with pockets of congestion as I hit junctions with I-495 and I-95. Then once inside I-95, traffic is complete sh*t. Last 5 miles is slower than my 10K running pace.

 

[SageBrush]

For this, you’ll need the size of your battery in kW

I'd be more confident in your advice if could learn the difference between a kW and a kWh

 

[SomeJoe7777]

I'd be more confident in your advice if could learn the difference between a kW and a kWh

kWh = kilowatt-hour = a quantity of energy. Equivalent in a fuel car to the quantity of the liquid fuel, typically measured in gallons.

kW = kilowatt = a RATE of energy use, also known as power. Equivalent in a fuel car to the fuel flow rate, which might be measured in gallons per hour. This is also equivalent to the mechanical rate of energy output, i.e. horsepower.

kW and kWh are related by the amount of time that a given quantity of energy is used. Example:

Let's say you have a light bulb that is rated at 100 watts. 100 watts is the energy use rate, AKA the power. If you have a quantity of energy of 100 watt-hours, this light bulb will use all of that energy in 1 hour. The same 100 watt-hours of energy, when used to power a 10 watt night light, will power it for 10 hours.

The size of a battery pack is measured in kWh. The model 3 LR has a battery pack that is approximately 75 kWh. This is like having a gas tank that can hold 20 gallons.

Let's use these figures to compute the rated efficiency of the Model 3 and the nominal power usage at 65 MPH.

Given that the battery pack is 75 kWh (we'll ignore unusable portions of the battery pack for now), and the rated range is 310 miles, then what is the rated efficiency?

75 kWh = 75,000 Wh / 310 miles = 241.9 Wh/mi. This number is pretty consistent with what people are seeing.

If we drive 65 mi/hr, what is the average power usage?

241.9 Wh/mi * 65 mi/hr = 15,725 Wh/h = 15,725 W = 15.72 kW.

How long will this drive take? We can calculate it two ways: 1. With the distance and speed, and 2. With the total energy and power.

1. 310 miles / 65 mi/hr = 4.77 hrs.

2. 75 kWh / 15.725 kW = 4.77 hrs.


We said earlier that kW is also equivalent to the mechanical rate of energy output, i.e. horsepower. What is the average horsepower output of the Model 3 over this drive?

1 HP = 746 W

15.72 kW = 15,725 W / 746 W/HP = 21 HP

 

[geometro]

Awful commute, huh? That's me trying to get to Boston in the morning from southern New Hampshire via I-93. First part of the commute is fairly fast - lots of 70mph travel with pockets of congestion as I hit junctions with I-495 and I-95. Then once inside I-95, traffic is complete sh*t. Last 5 miles is slower than my 10K running pace.

Yeah, that’s brutal.
But it’s informative too... as I have a similar distance and temp in the morning, but my speed is much higher and therefore, my efficiency is worse.

 

[Silent Ludicrosy]

Wow, that's really good. I'm happy when I get under 300kwh/mi. I'm guessing most of the efficiency gain is due to the switched reluctance motor, and the rest due to weight & aerodynamics.

Thanks for posting this, the Model S forum has a "lifetime Wh/mi" thread but I haven't seen many numbers posted for the Model 3.