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I understand "Rated Range" but PLEASE explain this to me

Discussion in 'Model S' started by themacs, Jan 2, 2016.

  1. themacs

    themacs Member

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    First my new P90D is my 2nd "S". I had a 2014 S 85 and owned it for a year. I have been through the #'s not making sense but starting to understand them.

    We bought a new P90D (I understand it is about the same range as an S 85) and I do love it BUT……

    Last night we charged it at home to 250 miles rated range. We took a trip in Southern California from San Clemente to Woodland Hill. 98% freeway driving Round trip was 168 miles by Mapquest AND the Tesla trip odometer.

    I drove with the cruise on between 70 and 75 MPH with little to NO slowing since we left today (Saturday no traffic) at 6:30 AM. NO heavy acceleration. All cruise. Really never touched the petals for 98% of the trip.

    So 168 miles and the Miles let upon conclusion was 19. So 250 rated miles and 19 left = 231 miles to go 168 miles. This will throw anyone off as to how far they can drive and plan. There is a 63 mile difference or about 1/3 more EXPECTED miles that were not attained.

    I understand that freeway driving at 70-75 gets less miles, but this IS a "D" and I would not expect 63 miles difference in a trip like this. The weather was about a 55 degree average due to early morning.

    So please help me understand because it seems we get NO where near the "miles" we expect on a P90D.

    I must be missing something so please point it out. I understand there are probably some points I'm missing but 33%.

    Thanks for an education :)

    Scott
     
  2. ndhaon91

    ndhaon91 Member

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    I've been meaning to ask basically the same question. No matter how conservatively I drive, I've never averaged less than about 410 wh/mi. So I'm not sure where the "rated" 300 wh/mi is coming from. Full disclosure: I've only been driving my 85D for 2 weeks.
     
  3. liuping

    liuping Active Member

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    75 MPH is give lower range than 65, and altitude changes, cabin heating, head wind, play a bug role as well.

    The best way to play around and see the effects of range, temperature, cargo weight, and altitude changes is to use EV Trip Planner. Pick a route, and play with the parameters. The speed factor lets you change the speed relative to the average speed on the roads, plus you can change outside temperature vs cabin temp, etc. Try a speed factor that gives you 65 MPH, then try one that give 75MPH, and you can see the effect on the Range.

    evtripplanner.com is pretty accurate, and I find it to currently be the best way to plan any long distance trip. I use a speed factor or 1.2, which gives about 85 MPH on I5. If weather conditions cause a drop in range (evtripplanner.com does not take into account head winds or rain), I can easily slow down to 75 or even 65 and have enough range to get to my destination.
     
  4. jeffro01

    jeffro01 Active Member

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    Hard to say... I have a 90D and have no problems staying around 330 wh/mi. One thing to note, did you have range mode enabled? If you didn't then you weren't benefitting from "torque sleep" which would have improved your range. Just figured I'd throw that out there...

    Jeff
     
  5. DougH

    DougH Active Member

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    Scott your signature is driving me nuts.

    It's "upgraded" not "up graded". You should also put commons after each option like jeffro01 did.


    Oh and your car is clearly defective, you should sell it to me :tongue:
     
  6. Caligula

    Caligula Member

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    Oh, the ironing.
     
  7. StaceyS

    StaceyS Member

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    Lots of factors go into energy consumption, but its important to note the conditions in which "Rated" is considered:

    Rated consumption happens at 55 mph, on flat ground, with no wind, at 70 degrees fahrenheit. There's weight consideration as well, but I can't recall it at the moment.

    If you're driving at 70-75 mph, you will be consuming more energy, and thus get fewer Rated Miles. If its cold out, you will get fewer rated miles. If there's a headwind, less miles. If you're going uphill, less miles. Combine all of that, less miles!

    We have a P85 and in the summer we were getting just below 300 wh/mile pretty easily (Oregon's highways are limited at 55 mph). Over Christmas, we did a 2500+ mile roadtrip from Oregon to Utah and back through CA. The average consumption was 368 wh/mile. We had a lot of 400+ wh/mile stretches where it was cold, we had headwinds and we were driving much faster than 55 (speed limit in ID and UT is 80). We saw noticable reduction in range. (Our lifetime average at the moment is 312 wh/mile.)

    Temperature has a very big impact as well. Over the course of two days, we drove from Salt Lake City to San Francisco, with a stop-over in Tahoe. The first day saw temps in the low to mid teens, and energy consumption was 400+ wh/mile. The next day descending from the Sierras and into the warmer temps of the Bay Area, our consumption was in the low 200s. Driving out of the Bay Area and up I-5 we saw closer to our typical driving consumption (300-320 wh/mile), but around Mt Shasta to Ashland, OR, consumption increased as the temps dropped and we climbed the passes.

    I usually like to keep those "rated" conditions in my head, so if I encounter the weather conditions and geography conducive to rated energy consumption, I can take advantage of that to either drive a bit faster, or use less energy.
     
  8. benf

    benf Member

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    To get the rated range, you have to average 290wh/mi. It's unrealistic in most situations. Unless you're stuck in traffic or driving down hill, you're simply not going to get that kind of range driving like a normal person in California. Look at your average wh/mi over the past 30 miles, and use that as an indication of the actual range you're going to get. For example, if you average 400wh/mi, that's ~28% decrease in rated range, so your 250 miles become 181 miles, which sounds roughly like what you got. Nothing out of the ordinary there, honestly.

    I always just assume ~25% less than the rated range unless conditions are REALLY bad (super cold, up hill the whole way, raining, windy, etc). This way I am never surprised.

    I wish they gave us a way to change the calculation it uses for range so I could see my "realistic" miles on the dash instead of "rated."
     
  9. Discoducky

    Discoducky Active Member

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    #9 Discoducky, Jan 2, 2016
    Last edited: Jan 2, 2016
    Try doing a test on a known stretch of road to see what you get with an out and back on a quiet stretch that is basically flat (using no regen) over at least 5 miles to establish a baseline at or above 40mph.

    Remember, anything that is out of perfect conditions results in less than rated range at 55mph.

    Things like:

    0. going into regen which is only about ~70% power generation (30% loss)
    1. temps under 70 to 80 degrees
    2. wind in any direction except tailwinds
    3. new tires that may have a higher rolling resistance
    4. underinflated or even normally inflated tires as opposed to slightly over inflated tires
    5. sizes higher than 19" like 21" have higher rolling resistance
    6. Anything but all-season tires like winter or summer which have higher rolling resistance
    7. Anything but low ride height for air-suspension above 50mph
    8. moisture, like rain, in the air
    9. high resistance pavement like rough roads with 'chipped-seal' gravel on top as opposed to new smooth asphalt
    10. non-waxed car as opposed to a very smooth waxed/polished/xpel'd car
    11. running the heater or A/C

    maybe I'm forgetting something else
     
  10. thecloud

    thecloud As rhythm raced inside, the ship came alive

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    You probably took the 405 over the Sepulveda Pass. Going uphill will take more power than driving on perfectly flat ground (which is how rated miles are calculated).

    Did you have climate control on for the entire drive? The heater can take a bite out of your range.
     
  11. liuping

    liuping Active Member

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    65 MPH, no head winds, moderate outside temperature, no cabin heating, nor rain/snow, flat roads, Range mode enabled, constant speed, you should be able to stay close to 300 wh/mi.

    Rated miles on my S85 required about 295 wh/mi. I'm not sure exactly what it is on my 90D. I do not worry about it much any more since they added the trip energy graph. If it starts predicting me arriving at the destination with less than 10%, I slow down, until the graph updates to closer to 10%.
     
  12. StaceyS

    StaceyS Member

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    Another big thing that can affect your average consumption, particularly in short trips is whether the car is preheated or not. If you don't preheat, the car uses onboard energy to heat the pack and cabin, which translates to significantly higher consumption. We have a 2 mile commute (which we mostly do by foot or by bike). If we do this without preheating the car, we get consumption rates of 800-1000 wh/mile. If I preheat the car, and increase the charge limit before we leave, the cabin and pack are fully heated, and we can get 300-400 wh/mile rates.
     
  13. liuping

    liuping Active Member

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    The rule of thumb I use for altitude: is 7 miles of Rated Miles lost per 1000 ft going up hill, and 4 miles of Rated Miles gained for each 1000 ft going down hill. This seems to work pretty well.
     
  14. nishy1

    nishy1 Member

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    So I have a p90d and drove from marina Del Rey to San Diego. Did it on tacc mostly. Was left with 40% battery left. Was pretty happy. But generally I never average less than 425kw/h in every day driving even without hitting insane mode much. I find that range mode helps. Also big thing here - make sure your regenerative braking is on. Without it that 425 kW/h will be more like 615.
     
  15. msnow

    msnow Active Member

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    Isn't "estimated range" the realistic number that factors in past driving?
     
  16. Zythryn

    Zythryn MS 70D, MX 90D

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    That is Ideal range.
    Rated range is based off the EPA testing.

    To the OP, many people have suggested reasons that may affect your range.
    I suspect headwind may have had an effect. Temperature would have a slight effect, although if you ran the heater, that would have had a bigger effect.
     
  17. AWDtsla

    AWDtsla Active Member

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    I'd like the see a video of someone achieving rated miles in a P*D without hearing everyone passing and honking or getting rear ended.
     
  18. ChadS

    ChadS Petroleum is for sissies

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    #18 ChadS, Jan 2, 2016
    Last edited: Jan 2, 2016
    HERE is a thread that describes factors that can affect range.

    You drove 168 miles. Going 70-75mph should add about 20% to your consumption. It being 55 degrees should add about 5%. Going up about 500' net should consume about 5 miles.

    So I'd expect you to have consumed 168 * 1.25 = 210 + 5 = 215 miles. You actually used 231. As others have suggested, not using range mode in a P90D could explain part of that difference. So could headwinds, start/stop elevations different than I assumed, or you were more towards 75mph or the temperature was a little lower than 55 or something like that. Or maybe tires:

    How many miles on the tires on the P90D? New tires are often a little less efficient. As are underinflated ones. And 21" tires use 3% more than 19". (The type of tire no doubt matters to, but I haven't seen really good comparison numbers on that).
     
  19. idoco

    idoco Member

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    Give it time. It will come down...hopefully.

    For our classic S with 40k+ miles on it lifetime avg is 316wh/mile. For long trips sub 300wh/mi is the norm(if it is not winter). Add 25% if cold.
     
  20. Muzzman1

    Muzzman1 Member

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    #20 Muzzman1, Jan 2, 2016
    Last edited: Jan 2, 2016
    A few ideas here might help @Scott.

    You have 21" wheels, Tesla considers that a 3% reduction.

    Did you have range mode on? If not, that's another 10% (correct me if I'm wrong) I read this a few days ago but I might have stumbled on the %'s
    Driving Range for the Model S Family | Tesla Motors

    Tire Break in period for the 1st 1000mi is 5%

    It's been particularly cold in the LA area, so the battery is not as efficient as it could be.
    Did you have the cabin HVAC on?

    I do that same round trip, but in the opposite direction every so often, and from where I am to San Clemente it's a 200mi round trip, and even with my 85D leaving at 90% I end up charging for a few mins.
     

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