Does the new Model S really get 400+ miles?

[Ciaopec]

Interesting test, cool that you did that. I would love to see 80 and 90mph averages, and the actual miles vs wh/mile/jargon. To the other persons point, wonder how much consumption changes when you go above 75mph (where most of my highway driving occurs). Would be a cool chart to have to understand actual range with highway speeds, avg temps and random terrain as that’s harder to control obv.

After 138000+ miles my personal experience is 75 is a great speed. How much different 70 is vs 75 vs 80 not worth worrying about IMHO. Too many variables to conveniently chart and if one could would you sit there referring to those charts?
I just go out and enjoy the drive. If there is a stretch without convenient charging, then by all means slow down; it does make a difference.
Don't drive faster than you can replace that energy by charging.

 

[TravelFree]

It looks like at 60 mph you would get 102500 / 244, or 420 miles. The epa runs the cars until they stop. Tesla says the batteries vary from 100 to 105 kwh, so I used the average. Even at the minimum of 100 kwh, you would get 409 miles.

When you did your tests did you run the car in both directions over the test road? Was there any wind? Even though you say there were no hills, was the starting and ending elevation the same. Even a small change in elevation can have an effect.

Assume you are familiar with the energy graph in the Tesla. What we did for the 5 minute run that was valid is achieve a near zero deviation in that graph so that for 5 minutes, the curve was a flat horizontal line. If there was a slight elevation in the road that graph is sensitive enough to show a momentary increase in the curve and decrease when going down hill on the other side. By validating a trial, 1 of 5, we assured the battery drain was constant. Each trial was then run in both directions on the same road rather than different roads. But finding that stretch of road where the curve was flat was the hard part. Also, no wind on our test day which was just luck.

The most difficult run was the 70mph run where traffic often caused a trial to have to abort. We found a section on I-10 between two overpasses where the elevation didn't change and no bends in the road. Trucks going too slow and traffic in the passing lane were the usual trouble spots. I think we did 9 runs to get 5 good flat line trials at 70mph.

I have read the EPA test method and it is pretty complicated. I had no intention of replicating that test.

There were two suggestions from the grandkid's science advisor that deviated from our original plan. She wanted us to use battery % and also begin each trial with a fully charged battery and run the test trial until the battery was dead. Obviously I busted out laughing when I read her suggestions. Using the Tesla energy graph and wh/mile is a much better way as once you achieve a flat run for 5 minutes the minimum scale in the graph, the average wh/mile is pretty consistent because the LiION battery has the same energy performance at 80% SOC as it does at 30% SOC when the battery temperature is maintained constant. Tesla owners know this. So all we had to do is drive for a reasonable distance to our test roads to get the battery temperature to be constant too. These variables that needed to be controlled had to be explained to the advisor who knew very little about how EV's work, especially a Tesla Model S LR+.

I also used two GoPro cameras, one on the energy graph and the other mounted on the steering column to document the speed and the trip miles in the display. My grandson did the logging of the data on paper as a requirement from the advisor.

 

[TravelFree]

One more thing that we did change in my original plan:
I wanted to see how much difference speeding makes in the wh/mile and had test runs planned for 80 and 90mph. This is often typical here as it is many parts of the country although you risk a speeding ticket. 70 mph is our max speed limit so since this was a science fare experiment supervised by the school, violating the law was not permitted lest the kid gets disqualified. That would be my fault.

 

[Trunk Gap]

Do it again with higher speeds Kidding, but not, but cool that you did it period.

Re higher speeds/worrying - I’ve dailied a Tesla for 5yrs now, and I don’t worry. It’s more curiosity, not worry. My results are what they are, factual, is what it is. Since I often drive over 75, curious to know what I’m giving up as I cruise at 85/90 (legally of course). Agree with you, 55-65 seems closer to stated range, 65-75 I give up a bit, 75-90 heavy range consumption, big difference.

 

[TravelFree]

rory, I haven't done this but I believe with 3 speed data points, you could create a curve to extrapolate an extension into higher speeds to see where the new range loss would be.

Pretty much, I'm a speed limit guy and drive relaxed in the right lane.

 

[TIppy]

This is the coast down curve that Tesla provides to the epa for the dyno simulation. It give the road load force as a function of speed:

pounds = 33.40 + 0.5032 * mph + 0.0106 mph * mph for Model S long range plus w/19" wheels, 5000 lbs.
At 65 mph this gives 110.9 lbf. Converting to newtons( X 4.44822) gives 493.3 N. Now multiply by the speed in meters per sec(29.1 m/s) to get the power of 14334.1 watts. This is the power the car is dissipating to maintain a speed of 65 mph.

The car must provide this power via the motors, but this process is not 100% efficient. There are 2% losses through the drive train, 6% in the motor and 1% in the inverter for a total efficiency of 91.2%. Therefor the battery must provide 14334.1 / 0.912, or 15717.2 watts.

To get the wh / mile we just divide the power by 65 mph to get 241.8 wh/mile. Car and Driver said they got 422 mile using 99.3 kwh. Using 241.8 wh/mile and 99.3 kwh gives 411 miles. There were probably some stretches of their drive where they were driving slower than 65 to turn around at each end of the various legs. Or the speedometer could be off by one percent or so. Then the wh / mile would be 239.1 giving a range of 415 mile using 99.3 kwh. And C&D miles would be 418.

Do it again with higher speeds

Just for Rory, using these equations these are the wh/mile I get for various speed:

60: 222
70: 263
80: 309
90: 359

 

[Cleo-n-Company]

This is the coast down curve that Tesla provides to the epa for the dyno simulation. It give the road load force as a function of speed:

pounds = 33.40 + 0.5032 * mph + 0.0106 mph * mph for Model S long range plus w/19" wheels, 5000 lbs.
At 65 mph this gives 110.9 lbf. Converting to newtons( X 4.44822) gives 493.3 N. Now multiply by the speed in meters per sec(29.1 m/s) to get the power of 14334.1 watts. This is the power the car is dissipating to maintain a speed of 65 mph.

The car must provide this power via the motors, but this process is not 100% efficient. There are 2% losses through the drive train, 6% in the motor and 1% in the inverter for a total efficiency of 91.2%. Therefor the battery must provide 14334.1 / 0.912, or 15717.2 watts.

To get the wh / mile we just divide the power by 65 mph to get 241.8 wh/mile. Car and Driver said they got 422 mile using 99.3 kwh. Using 241.8 wh/mile and 99.3 kwh gives 411 miles. There were probably some stretches of their drive where they were driving slower than 65 to turn around at each end of the various legs. Or the speedometer could be off by one percent or so. Then the wh / mile would be 239.1 giving a range of 415 mile using 99.3 kwh. And C&D miles would be 418.



Just for Rory, using these equations these are the wh/mile I get for various speed:

60: 222
70: 263
80: 309
90: 359

What if I change the radio station or turn on a window wiper during this exercise ?

 

[Zextraterrestrial]

So what you're really saying is... there isn't a single scenario where any of us can expect the 400 mile range.

This is what we refer to as marketing.

false. @jerry33 would get 450 miles

 

[Cleo-n-Company]

false. @jerry33 would get 450 miles

@jerry33 - I hardly know thee - but one of your pals on the forum seems to indicate you are the magic man when it comes to range expansion.

 

[Uncle Paul]

Some have posted runs, using hypermiling techniques well over 500 miles per charge.

If you drive more agressively than the EPA testing you will get worse range.
If you drive more consevativly than the EPA testing you will get better range.

 

[jerry33]

@jerry33 - I hardly know thee - but one of your pals on the forum seems to indicate you are the magic man when it comes to range expansion.

LOL. That was true with the 2013 S (145 Wh/mi lifetime average over 126K miles), but Tesla has dumbed down the interface in the newer cars so you can't drive to the numbers anymore. I don't even try in the new X. Perhaps someone will come up with a Wh gauge that has the tick marks where you need them. (10,000, 20,000 40,000). I'm not sure who's bright idea it was to make the first tick 75,000 but they might as well not have even bothered.

 

[Trunk Gap]

Testing right now. 55 degrees out. Flat straight road. 85mph.
Stated range 155. Instant range says 320-370 wh/mi. Projected instant range hovering between 92-104. 88 actual miles to the supercharger.
My bet says projected instant is darn close to what I will experience.

 

[dannycamps]

My bet says projected instant is darn close to what I will experience.

The energy graphs in the car are pretty accurate especially the instant with a short (5 mile) data sample size. I find the trip consumption graph to be pretty much spot on once the kWh figures stabilize.

 

[Trunk Gap]

Got to the SC with about 40 miles of stated range.
Averaged 440 wh/mi
So with 155 stated, went 88 miles, got there with 40.

So at maybe 85mph avg, took about 115 miles of stated range to go 88 miles. Better than I thought.

Second leg of trip had 320 miles of stated range. 193 actual miles to destination. Got to the destination with 21 miles of stated range left. Meaning it consumed 299 stated miles to go 193 actual miles. This is more what I’m used to experiencing.

In case anyone is interested.

 

[Tiger]

See Teslike or TeslaBjorn for range information

 

[quickstrike12]

This is the coast down curve that Tesla provides to the epa for the dyno simulation. It give the road load force as a function of speed:

pounds = 33.40 + 0.5032 * mph + 0.0106 mph * mph for Model S long range plus w/19" wheels, 5000 lbs.
At 65 mph this gives 110.9 lbf. Converting to newtons( X 4.44822) gives 493.3 N. Now multiply by the speed in meters per sec(29.1 m/s) to get the power of 14334.1 watts. This is the power the car is dissipating to maintain a speed of 65 mph.

The car must provide this power via the motors, but this process is not 100% efficient. There are 2% losses through the drive train, 6% in the motor and 1% in the inverter for a total efficiency of 91.2%. Therefor the battery must provide 14334.1 / 0.912, or 15717.2 watts.

To get the wh / mile we just divide the power by 65 mph to get 241.8 wh/mile. Car and Driver said they got 422 mile using 99.3 kwh. Using 241.8 wh/mile and 99.3 kwh gives 411 miles. There were probably some stretches of their drive where they were driving slower than 65 to turn around at each end of the various legs. Or the speedometer could be off by one percent or so. Then the wh / mile would be 239.1 giving a range of 415 mile using 99.3 kwh. And C&D miles would be 418.



Just for Rory, using these equations these are the wh/mile I get for various speed:

60: 222
70: 263
80: 309
90: 359

Help me understand please. I’m following the math and it makes perfect sense. I understand. But doesn’t that make the required power curve for against speed increases linear? I understood that there are points of diminishing returns when increasing speed. And the curve steepened greatly somewhere after 75 or 80 mph?
is that not the case?
It’s my understanding that the drag coefficient increases greatly as speed increases as well as rolling resistance is not linear. Thereby making it not quite as simple as just the math of power of speed.
Drag coefficient in aviation is very similar.

 

[quickstrike12]

Looks like the drag coefficient of a model S is 0.24. so maybe using
The formula P = FdV , with Fd being drag coefficient of 0.24 might work?

 

[Jughead135]

There is one habit I have that may be gaming the system a little bit. When driving on the freeway, I NEVER regen unless I must in order to slow down from hitting something. So if I need to slow down, I lift up just enough to coast rather than use regen...letting resistance slow me down. So if I want to slow from 75 to 70 because I'm coming up to traffic, I essentially coast down to 70 without regen.

3. Terrain matters but only if you fail to properly regen.

I'd like some help understanding this, please. Short of turning the regen off, how does one "fail to properly regen" and/or "coast rather than use regen"?

My understanding (flawed, perhaps?) is that regen kicks in any time the car has more energy than needed to maintain the desired speed (slowing down, or cruising downhill), as indicated by the driver's demand via the accelerator pedal. I haven't studied it, but the energy graph seems to agree with that: if I'm slowing down and/or going downhill, it trends downward; if I'm slowing down "rapidly enough" or going down a "long enough," "steep enough" hill, it trends into the green (providing "regen" power to the battery).

What am I missing in your respective points?

 

[croman]

Friction brakes kill efficiency. Regen had limits which are exacerbated by SoC, ambient temp, pack temp, and peak power demand.

 

[comanchepilot]

rumor has it that they have now bumped it to 409 miles - but - no one is ever going to really know in the real world since no one will ever drive it until it stops unless they're being followed by a diesel powered generator which can get them juice to make it to a supercharger. . . .