LR True Range -- Part II, Early Evidence

[Electroman]

Only if someone actually goes 30mph the entire time. Lets say I'm driving a car with the defaults from ecomodder's power versus speed calculator(Aerodynamic & rolling resistance, power & MPG calculator - EcoModder.com), and have a 20 miles commute and...

1) I travel 10 miles at 80mph and 10 miles at 20mph, for an overall average of 32mph (20 miles/(.125h + .5h)). Energy consumption at 80mph is about 250Wh/mile, and at 20mph about 40Wh/mile, for an average of 145+Wh/mile.

Or...

2) I travel all 20 miles at 32mph, and my energy consumption is 60+Wh/mile.

Same average speed, very different energy use. Miles per hour is a function of speed, while Wh/mile is strongly a function of speed squared. The more our range of speeds diverges from our average speed, the higher our energy consumption will be even if the average speeds are the same.

Exactly.

Don't get carried away by average speeds. Averages speed is really not an useful metric in calculating efficiency.

You could have driven 80mph all the way and the last two miles thru stop lights. That would give you a much less average speed.

 

[jerjozwik]

What's your S at?

all time best ever was this:

but... normally i get into the 270 1 way and ~320 for the day.

 

[jerjozwik]

Exactly.
Don't get carried away by average speeds. Averages speed is really not an useful metric in calculating efficiency.
You could have driven 80mph all the way and the last two miles thru stop lights. That would give you a much less average speed.

yep, my night time route is:
1.64 miles of stop lights.
4 miles of stop and go highway.
8 miles of 60-75 mph cruising highway.
3.5 miles stop and go highway.
5.7 miles stop lights.

 

[jerjozwik]

i tried a bit harder today:

 

[Electroman]

169 wh/mile? if you can manage that for a full battery you will get 461 miles (78000/169)

 

[gregincal]

all time best ever was this:

but... normally i get into the 270 1 way and ~320 for the day.

OK, I'm not getting quite as dramatic a difference as you, but the Model 3 is more efficient than I expected. My commute is a bit more than 30 miles each way and it takes about 45 minutes. It's a mix as well, a climb over an 1800 foot pass at 50-60 mph, some 70 mph freeway driving, some stop and go and some city streets. My normal round trip in my Model S was about 285-295 wh/mile. Here is a good commute in my Model S (from a couple weeks ago, just before I got my Model 3):

That used 72 rated miles for about 68.8 commute miles, or 1.05 rated mile per commute mile.

Today I had my best yet Model 3 commute:

That used 58 rated miles for about 65 commute miles. That's .89 rated mile per commute mile. In 5 years I'm pretty sure I never once use less rated miles that actual miles on a commute in my Model S. My results last week weren't nearly this good, so I'll be interested to see what I get in the coming days.

 

[jerjozwik]

@gregincal, what is your tire pressure set to? also what temperature was the drive? this last example was around 22*c

 

[Electroman]

.. and its only going to get better as the temps warm up a bit. So you haven't seen the best yet..

 

[run-the-joules]

Averaging around 270 myself. Some of y'all have a real light touch on the throttle that I simply don't have the patience for Don't recall if it was here or reddit but someone was claiming he tries not to let the power bar go past the "H" in MPH, and claimed he was keeping pace with traffic. I suspect that fellow lives somewhere with an average age of about 90, because that is slllloooowwwwww acceleration.

 

[gregincal]

Averaging around 270 myself. Some of y'all have a real light touch on the throttle that I simply don't have the patience for Don't recall if it was here or reddit but someone was claiming he tries not to let the power bar go past the "H" in MPH, and claimed he was keeping pace with traffic. I suspect that fellow lives somewhere with an average age of about 90, because that is slllloooowwwwww acceleration.

It helps if you commute in traffic. The Model 3 is way more efficient in stop and go than the Model S. The highway 17 section of my commute is generally quite fun, but 60 mph is fast for that section. When I hit the flat straight freeways of the Bay Area it's time to slow down.

 

[jerjozwik]

Averaging around 270 myself. Some of y'all have a real light touch on the throttle that I simply don't have the patience for Don't recall if it was here or reddit but someone was claiming he tries not to let the power bar go past the "H" in MPH, and claimed he was keeping pace with traffic. I suspect that fellow lives somewhere with an average age of about 90, because that is slllloooowwwwww acceleration.

90... i got dash cam footage to prove it. you are getting spoiled by your ev accelerator.

 

[TonyWilliams]

Lots of anecdotes on this thread. Range, quite simply, is stored energy multiplied by consumption rate of that stored energy.

miles or km = available kWh * consumption (watthour per mile or km)

We know that battery holds 78.x available energy, since Tesla would get themselves in a world of hurt if that was not true. Therefore, a fully charged, warm, new condition battery without degradation should provide:

miles or km = 78kWh * consumption

For those that just want the range to "0" miles or km, then use 73kWh. Easy.

So, the ONLY addtional variable is the actual or estimated consumption rate. I already know that I get about 250 watthours / 0.250kWh per mile or 4 miles per kWh at 70 mph on a level, dry surface highway, without significant wind:

312 miles = 78kWh * (1 / 0.250kWh)
312 miles = 78kWh * 4 miles per kWh

 

[Candleflame]

There is a reserve on S/X today. You can go 10 Miles when the range says 0. All I'm saying is that they are doing the same thing only more because they model 3 is more of a mass market car and people won't spend hours on a message board learning every detail about how the battery works in an electric car. Most won't read the manual that comes with the car either, they will just assume there is a reserve. Because every car for decades can drive many miles on empty.

BMW E46 sedan has no fuel reserve past 0. The BMW e46 compact DOES have a 3L reserve past 0. Fuel tank size is the same (63L) for both.

 

[Hertog_Martin]

Come on, with nearly 10k M3's on the road soon, there must be enough data points now to know the wH/mi for every speed and condition now.

How is there hardly more information available on range performance now compared to half a year ago??

 

[Reciprocity]

BMW E46 sedan has no fuel reserve past 0. The BMW e46 compact DOES have a 3L reserve past 0. Fuel tank size is the same (63L) for both.

Mostly talking about the average car, not a car with some fancy injection system. There are tens of millions of cars sold every year for decades that don't run out of gas when the needle hits E. This has trained billions of drivers that the car doesn't need to be towed if the needle hits E. It's as simple as that. I'm not talking about a special gas tank for reserve fuel. I'm talking about trained behaviour of your average driver who doesn't read the manual on the car and doesn't go to a fan club forum to read every thing about the car and that doesn't even listen to the auto dealer when he says what it hits zero, it's really 0. I have never owned a car in my life including my S and X that did not have a reserve below zero. The model 3 reserve is just larger for the common driver. It's as clear as day.

 

[T34ME]

I suspect that fellow lives somewhere with an average age of about 90, because that is slllloooowwwwww acceleration.

Well..................you have me pegged, that is my demographic and a geriatric hypermiler. I expect to average 220 W/mi city and highway. But I am quite good looking for my age.

I hope with your lead foot that you will live long enough to reach that exalted age some day so you too can go slow and enjoy the fruits of hard work and environmental responsibility (but you will never be as good looking as I am).

 

[Candleflame]

Exactly.

Don't get carried away by average speeds. Averages speed is really not an useful metric in calculating efficiency.

You could have driven 80mph all the way and the last two miles thru stop lights. That would give you a much less average speed.

Yeah, it's very interesting actually driving from i.e. France to Germany and planning to i.e. driving 140kmh in france and 180kmh in Germany and to then check your average speed and see how low it actually is in reality factoring in reduced speed areas, metro areas etc.

 

[svp6]

Why do people keep talking about 78 kWh battery available? By my calculations it is closer to 70-72 kWh. In every single trip I did so far the actual kWh used divided by the rated range miles used is rock solid around 232-233 Wh/mi. If you multiply that by the optimistic 310 miles you get a total available battery of 72.23 kWh, if you multiply by my actual max range (5 full charges so far, they showed 300,300, 301, 303, 301 miles), 70.1 kWh.

 

[Zoomit]

Why do people keep talking about 78 kWh battery available?

It’s possible there’s a ~6 kWh buffer below 0 miles range that remains available for use. That could be the difference between what you have seen and the EPA filing where Tesla mentioned 78 kWh of usable capacity.

 

[svp6]

It’s possible there’s a ~6 kWh buffer below 0 miles range that remains available for use. That could be the difference between what you have seen and the EPA filing where Tesla mentioned 78 kWh of usable capacity.

If they use the same approach as in Model S / X, there should be nothing left at 0 miles - multiple threads where people warn about not trying to drive below 0. There most definitely is a reserve to prevent bricking - but that cannot be accessed. Now if wk057 gets a 3 to play with it, we would know