# Forums

## Well? What is your average Wh/m?

I drove 204 miles as carefully as I could, and managed 348 Wh/mi to get home with 21 miles of range to spare.

My average over 1200 or so miles is closer to 375, and it isn't uncommon to see 400Wh/mi with "normal" driving.

What are you seeing?

The original thoughts of "300 mile range" seem out of the question here in the midwest.

STEVEZ | 24. November 2012

I've averaged 331 Wh/mi over the first 1500 miles. I occasionally drive 75-80 mph on the freeway, but more often my top speed on any trip is in the 50-65 mph range, and grocery runs top out at 45 mph. I've got a non-Performance model with 19" wheels; full performance starts and sustained high speeds are what push up Wh/mi the most.

Timo | 24. November 2012

85000Wh/331Wh/mi = 256miles. Still quite high if you compare it to reviews.

jkirkebo | 25. November 2012

If I understand correctly, 265 miles is based on 308Wh/mile. 265*308=~81,6kWh. The rest is supposedly kept as a reserve.

This would make his range 246 miles.

Sparrow | 25. November 2012

I have only driven 500 miles and so far am at an even 300wh/mile. It dropped to that level from 304 wh/mile after a 90 mile mostly highway drive at 60mph. I do tend to drive conservatively.

Timo | 25. November 2012

Elon said at one point something like this "lets see who gets 400 miles on one charge first".

85000Wh/400miles = 212.5Wh/mile. That's roughly 2/3 of that 308Wh/mile.

Which speed gives you approx that number? Is it close to that in city traffic? Blog chart puts 400 mile range at roughly 37mph, is that even close to real life figure?

Equest | 25. November 2012

So I have 1,644 miles and my average since day 1 is 344Wh/mile.
However just a few weeks ago I was averaging 331. My driving habits haven't really changed; however, 2 things have changed. First I switched from the 21" performance wheels and tires to the 19" wheels and snows. Also, being in NJ the weather has been much colder the last few weeks (down around 32 degrees at night. With the cold the car apparently does not coast regen the battery until the battery pack warms up. For instance last night it took a good 15 minutes to be able to regen fully when coasting. There is a dashed yellow line that appears in the regen area of the speedometer display. This is also probably negatively impacting the Wh/mile rate.

Most of my driving has been back roads but I live in a hilly area and that results in not being able to achieve a rate similar to some of those above. I drive about 20% highway and 80% back roads. I will be taking my first long trip this week from NJ to CT to Boston to NH to Mid Mass to CT to NJ which is about a total distance of 500 miles. I am going to reset the trip odometer and see what my rating is based on mostly highway mileage probably at an average speed of around 70 MPH. Might also see how it handles in the snow as we are expecting a snow event in the Northeast this Tues/Wed.

Klaus | 25. November 2012

Did a 255 mile trip yesterday and averaged 295 Wh/mile. That was on a single charge. Had 10 miles left when I got home. Average for 2500 miles is 310Wh/mile. BTW, my trip had 4 adult aboard.

mthanos | 25. November 2012

Can everyone post which version s they have, ie performance or not?

Rod and Barbara | 25. November 2012

After 3,700 miles our average is 318 Wh/Mile in our 85kWh non-performance Signature Model S.

jkirkebo is right, the usable battery capacity is less than 85kWh. Based on empirical data I’m collecting in our Model S, and assuming a normal distribution, the usable battery capacity is between 80.8 and 81.7 kWh (99% confidence level). As an aside, this puts the Rated Mile efficiency between 305 and 308 Wh/Mile.

sergiyz | 25. November 2012

perf, 377Wh/mi

portia | 26. November 2012

1700 miles, sig performance, about 352 wh/m, there was the 1021 mile road trip, the rest are maybe half lcal half highway. I don't drive particularly slowly.

TimS | 26. November 2012

I don't doubt that temperature has some impact on the matter... It does get cold in Wisconsin. (not to mention it isn't exactly flat)

Mine is Signature Performance.

In general, I drive it like I would drive any other car. I use the climate control to stay comfortable, I turn on the windshield defroster when necessary to maintain the ability to actually see the road. You know.... the little things.

Thoughts of 300 miles or more seem less like driving and more like theoretical driving conditions and ridiculously slow accelerations, only driving with the wind, tailgating 10ft behind a semi trailer.

For me, Chicago is 100 miles away. I've made the round trip, but it wasn't comfortable - was not able to "keep up with traffic" without giving up on being confident that I'd make it home.

Vic M | 27. November 2012

On my commute (Silicon Valley traffic), I get 289 Wh/m. For high speed trips it is more like 340.

Kauai | 27. November 2012

355 Wh/mile over the fist ~400 miles. Used for Silicon Valley 280 commute, e.g. periodic burst to 85mph and long sustained stretches 70-80mph up and down hills some city streets and the occasional stop and go back up

dahtye | 27. November 2012

Sig performance, 1800 miles, getting consistent 350Wh/mile. Earlier, I was getting 335Wh/m, but I've started driving more "spiritedly" lately. As of today, I've had my Model S for exactly 1 month!

Brian H | 27. November 2012

@Vic M;
Very glad to see you say that!

Cross-posted:
... when EPA came out with the ratings saying city driving got lower MPGe than highway, I was very dubious. Didn't fit the BEV profile at all, or the early beta reports.
.
But late in the game, it seems Elon ordained a retuning to give more oomph in the passing ranges. It now occurs to me that since you don't get something for nothing, that this moved the power band "north" at the expense of low RPM efficiency. Don't know how this was achieved, though.

Volker.Berlin | 28. November 2012

Interesting comparison: I just stumbled across a comment from an i-MiEV driver who bragged that he achieves 255 Wh/mi (real-world driving averaged over all seasons incl. heating and accessories). Given the size, weight and power of an i-MiEV, it occurs to me that the Model S' power consumption compares favorably.

Volker.Berlin | 28. November 2012

In all fairness, it should be noted that the above mentioned 255 Wh/mi for the i-MiEV (real-world driving averaged over all seasons incl. heating and accessories) was measured from the grid, not from the battery, i.e., while all numbers for the Model S that are mentioned in this thread ignore charging losses, the i-MiEV mileage includes them.

Timo | 28. November 2012

It's the weight of the Model S which makes it use more than i-MiEV. You just can't beat rolling resistance difference by better engineering if other car weights only half of your car.

Also frontal area is quite a bit bigger (i-MiEV is only ~1500mm wide while Model S is more than 2000mm, about same height).

Considering those Model S is very efficient vehicle, though I still wonder why does it weight so much.

8000 * 46g (about 90kWh) is only 368kg and car weights over 2100. That's a lot when almost entire car has been made using aluminum. Is it the wiring? Does the liquid cooling add hundreds of kg? Motor is tiny, but it probably still is (with PEM) 100-150kg. Battery pack casing? Bottom armor protecting the batteries? All of the above?

murraypetera | 28. November 2012

I have created the following google doc/form for entry of date to get some Avg numbers

I only have total avg calculated at this point but intend to add per type of car avg.

The raw data can be seen here and the avg calc in the I & J columns

jkirkebo | 28. November 2012

My Leaf is at 286Wh/mile so far this year, measured from the battery. I often do not drive very economically as we have a lot of quick chargers around now. I'd rather use heat and travel at a good speed and use 10 minutes for free QC, than travel slowly while freezing ;)

Velo1 | 28. November 2012

A bit off topic, but for those with experience, if the reserve power indicates 10 miles, how accurate is this value? I would expect it will depend on driving style for the balance of the power, but thought I'd ask what some are experiencing. Thanks

Andrew18 | 28. November 2012

I think I'm driving her too hard. I'm at about 400 Wh/ mi, after 2 weeks. I can't resist!! I only drive about 40 miles a day, so I don't care.

Brian H | 28. November 2012

re: Velo1's question;

Suggestion: when the projected miles is very low, reset the system to the lowest averaging base value, and watch as you drive. That should show the effects of "careful driving" best for that last leg.

Velo1 | 28. November 2012

Thanks H.

Brian H | 28. November 2012

Andrew;
Hey, when you've got a rocket in your pocket ... ;0 ;) ;P

Brian H | 28. November 2012

Andrew;
I can just hear you: "Ohboyohboyoboy! Commute time again!"

Rod and Barbara | 29. November 2012

@ Velo1 – When the Rated Miles Remaining indicates 10 miles, you will be able to drive 10 more miles if you drive at 307 Wh/Mile. You will drive more or less than 10 miles if your energy use is better or worse than 307 Wh/Mile. You can monitor your current energy use on the Energy app on the 17” touch screen. When the Rated Miles Remaining reaches 0, the car stops, there is no reserve capability.

@ Brian H – What does “reset the system to the lowest averaging base value, and watch as you drive” mean? I’m not sure you can do what you are referring to in the Model S.

Brian H | 29. November 2012

You have "projected" options, don't you? Averaging over 30 miles, or less? Pick the lowest figure, that will give the best instantaneous read on how far you have left if you carry on as you've just been doing. Eg, show the effect of slowing down.

Rod and Barbara | 29. November 2012

@ Brian H - There are only two range predictions in the Model S - Rated Miles Remaining and Projected Miles Remaining. Rated Miles Remaining is based on a constant power usage derived from the EPA 5-cycle test. Although Tesla does not advertise this value, based on empirical data I collected I determined that is about 307 Wh/Mile. Projected Miles Remaining is based on the Wh/Mile experienced over the last 30 miles and is constantly updating as you drive. You cannot select a different mile range or a different efficiency to be used in the Projected Miles calculation. In addition to monitoring the Energy app display, you can also reset one of the two trip odometers. The trip odometers display miles traveled, kWhr expended, and power usage in Wh/Mile since the last reset. So with 10 Rated Miles Remaining, you could reset a trip odometer and then monitor the Wh/Mile as you drive. If it is more than 307 you will be able to drive less than 10 miles and if it is less than 307 you will be able to drive more than 10 miles.

kent | 29. November 2012

First I'm in Ohio and heat is required.

Delivered Nov. 2nd - 1511 Miles - 548.5 kWh - Average - 363 Wh/mi

This would be much lower, but I've given at least 12 test rides with full acceleration to prove that an electric was not slow. Once those rides are over and the newness goes away, I image I'll average about 320 during the colder months and less during the summer.

Brian H | 29. November 2012

R&B;
bottom of p17 of the Owners' Guide:

"UNDERSTANDING ENERGY USE
To display how much energy Model S has been using, touch the Energy
APP on the touchscreen. This displays a graph that you can pinch or
expand to display the energy used over the past 5,15 or 30 miles. This is a useful way to show how driving habits and condition impact the amount of energy use"

I learned this from cinergy's videos!!

;)

John-V707 | 29. November 2012

I've been driving in Seattle, in the dark (mornings and evenings), with lights on, heaters on (35-50 degrees outside), in a mix of rush hour traffic and highway speeds, in a hilly envoronment. I'm seeing around 425 WH/mi average over the first few hundred miles (and pretty consistent on a daily basis), or roughly 170 miles on a standard charge. I hope due to the above, that in summer (or on the highway) I will see a higher range.

For the EPA estimate: with 85kWH and 265 miles EPA, that is 320.75 WH/mi (e.g. ~320); it's straight division. For the "standard" charge, I see a rated 238-240 miles fully charged - which is almost exactly 90% of 85KWH at 320. (240/265 is also 90%). The "standard" charge cycle is therefore 90% of the full change.

Rod and Barbara | 29. November 2012

@ Brian H – I am very familiar with both the Guide For Owners and the Energy app on the touch screen. In your second to last post you said, “Pick the lowest figure, that will give the best instantaneous read on how far you have left if you carry on as you've just been doing.” The Energy app screen you reference in your last post does not provide an “instantaneous read of how far you have left.” The Energy app screen can be set to display the last 30, 15 or 5 miles. The screen displays the instantaneous power use in Wh/Mile, the average power use in Wh/Mile over the selected miles (30, 15 or 5) and a graphic representation of the power use over the selected miles. To use this screen to obtain an “instantaneous read of how far you have left” one would have to make the following calculation: (Rated Miles Reamining) x (307) /(average Wh/Mile from Energy screen) = miles remaining if driving efficiency does not change from the average displayed on the Energy screen. I find my previous recommendations more useful for determining how things are progressing near the end of a battery charge.

Rod and Barbara | 29. November 2012

@ John-S886 – You are correct that determining the power use of a Rated Mile involves straight division once you know the usable battery capacity and the 5-cycle EPA mile value. Fortunately, the 5-cycle EPA value is an official, published number, 265 miles. However, the usable battery capacity is not published anywhere and it is definitely less than 85 kWh. I have collected extensive data while driving over 3,900 miles in my Model S. Based on my data, the usable battery capacity is about 81.3 kWh (assuming a normal distribution, it is 81.3 kWh + or – 0.4 kWh with a 99% confidence level). Now the straight division will yield the correct value for the power use of a Rated Mile, about 307 Wh/Mile.

With respect to your calculation of a standard level charge there is another issue at play. When the Rated Miles Remaining (RMR) reaches 0, there is still 5% to 7% State of Charge (SOC) left in the battery. I have driven my car to this point on two occasions. What this means is that you cannot divide RMR by 265 to determine the battery SOC. The battery graphic displayed on the Charge screen on the touch screen is a very good estimate of the SOC of the battery. Tesla has informed me that the standard level charge changed from 85% to 87% SOC with software version 1.9.17 which was released on 9/26/12. Apparently this 87% value isn’t a hard number since I routinely see 93% SOC on my car following a standard level charge with the RMR of about 240 to 244 miles.

Getting Amped Again | 29. November 2012

It looks like real world conditions can possibly knock the actual range to 50-70% of the advertised numbers, and it's not even winter yet. This is a great thread because purchase decisions are being made on the advertised ranges and the real world data is indeed "eye opening".

I finalized with a 60 kWh battery to get the sub-six second 0-60 time, but now I realize I need it for the range also. Those considering a 40 kWh battery are going to get less than 100 miles if they live in a hilly area and have real winter weather. Choose wisely!

sergiyz | 30. November 2012

If you take an ICE car, would you normally drive with less than 30 mi range left ?
It's as hard (if not harder) to predict how long that would last since different manufacturers have different ideas about fuel tank size and reserve.
85kWh battery is definitely worth the expense so you don't have to wait for your range to drop to 10 mi and then guess whether you make it or not.
It's probably good for science but is unnecessary in most cases.
If I know I'm averaging 378Wh/mi, I wouldn't drive over 200 mi between charges and realistically I wouldn't let it drop under 30 miles, so probably 170-180 miles tops.
It's a bit harder than ICE cars at the moment since in populated areas you're almost always within 30 mi range from a gas station and not necessarily within same range from a charging station.
We'll get there with EVs in a couple of years, thanks to Tesla that made a real and desirable electric car justifying an investment in charging infrastructure.

Timo | 30. November 2012

@Rod and Barbara, can you program display to show you what your average power usage should be to reach some point into GPS map at your current speed? AFAIK you get your current power usage in dash. Am I correct in that?

If there is no such display I think that would be nice to get into Model S power display options. Not just your Wh/mi but W at your current speed. Kind of "don't go above that line, and you will be fine".

RZitrin1 | 30. November 2012

Rod, you can, however, choose a last 15 miles or 5 miles energy use chart on either the touch screen or the dash. Not sure this helps a lot.

Brian and others: I'm doing almost all city driving in SF, up and down, up and down, and I'm over 400 in that venue. Out on the road is much better.

Seems to me that 307 is a very difficult goal to attain, so we all ought to be cautious at the end of rated miles.

Richard

Rod and Barbara | 30. November 2012

@ Timo - The display of needed power usage to reach a location does not exist in the Model S. There are multiple displays available to monitor current power usage or the average power usage over the last 30, 15 or 5 miles.

Brian H | 30. November 2012

R&B;
Indeed, "instantaneous" is a bit strong. The 5 mile average would give a more responsive indication of how you are doing squeezing out the last few miles, tho'. Imagine the opposite situation, if you only had projected range based on, say, the last 1000 miles; that wouldn't tell you much about how likely you were to make it home when you're hyper-crawling along!