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Pushing it S 70D

Discussion in 'Model S' started by Missile Toad, Oct 12, 2016.

?

I figure an extra 3.0 miles is hidden in the tank

  1. Damn right!

    22.6%
  2. Seriously? 2.0 at best.

    0 vote(s)
    0.0%
  3. Only a madman thinks there is more than 1.0.

    6.5%
  4. Tesla is infallable. 0.0 extra.

    22.6%
  5. Are you guys nuts? Never arrive with less than 5 RM reported !

    48.4%
  1. Missile Toad

    Missile Toad Member

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    So, I'm noticing that Wh/mi is improved on side streets versus highway driving at 75-80 MPH. Having done that, I ran five trials on EVTripPlanner.com to see what the Wh/mi in a hypothetical drive, via mostly side streets, to cover a final 5 miles to some superchargers. My info averages to 215 Wh/mi in largely flat-land no-wind scenarios. This is versus the Tesla-implied 'rated mile' equivalent of 256 Wh/mi that my S 70D routinely reports when I look to the trip odometers (simply the Wh divided by the loss in Rated Mile (RM) for that excursion). This leads to about a 20% increased actual range in the side-street regime versus the reported RM.

    Now, I recently experienced a powerless* coast from 80 MPH down to 0 on fair weather, no wind, 0 incline day... and I estimate I covered about 1.5 miles.

    Further, assume that the instrument cluster (IC) report of Range Miles applies normal rounding rules (round up if decimal is .5 or higher). So a pessimistic view is that 13 RM reported is really 12.5 RM in the internal Tesla formula. So, what is the real range, when dropping off a highway at 75ish MPH?
    12.5 mi x 1.20 = 15
    adding a pessimistic coast in:
    15 + 0.9 = 15.9 mi

    IC reported Side theory**
    Range Mi street mi
    20 ... 23.4 24.5
    18 21 21.9
    14 16.2 17.1​
    * I was powerless... pedal to the metal = nothing.
    ** adds about 0.9 mi for coasting

    So I'm getting, normally, flat, no wind, etc., an extra 3.0 mile when dropping off the highways. Please comment.
     
  2. Missile Toad

    Missile Toad Member

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    Houston
    Trying different formatting (Courier New... or is TMC just teasing us with that font):

     
  3. Max*

    Max* Autopilot != Autonomous

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    I never understood people who turn off the AC, throw their kids out the window, suck in their bellies thinking it'll reduce the weight hoping to get an extra 0.754321 miles out of the car.

    Drive it, enjoy it, stop worrying.
     
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  4. CHG-ON

    CHG-ON Still in love after all these miles

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    How the F are you getting 215 w/mi?!!! I have a P85+ and have never gotten below 290, which only happened after the 8.0 update on the highway, of which I am suspect. Prior to that, my avg w/mi since delivery on 10/14 has been 334.

    Oh, and as far as kids: toss 'em! Suck in the belly: waaaay past that stage. Turn off A/C: not on your life!:)

    And @Max* , I totally agree!!!
     
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  5. Missile Toad

    Missile Toad Member

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    CHG-ON, 220 Wh/mi is what I personally achieve on flat, no-wind 32 MPH test. A longer test at 48 MPH yielded 228. Now I'm driving a S 70D 19" wheel, which is lighter than your P85+. The 215 Wh/mi is the figure that EVTripplanner estimates, which I assume does not count any previously 'stored' kinetic energy that comes from coasting off the highway. What it leaves me to conclude is that EVTripplanner must be setting very low speed assumptions on the order of 25-30 MPH for the local driving. Also, I did throw out my kids for these tests and for the 32 MPH, I found an adorable little dog, which I decorated with one lone antler, to harness as a 'supplemental power supply'. ;) They don't call me 'green' for nothing.
     
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  6. RogerHScott

    RogerHScott Active Member

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    What kind of Wh/mi did you get on your way up to the top of Mount Krumpet? :)
    "Driving an ICE is a vice I can't stand even once or twice!"
     
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  7. ReddyLeaf

    ReddyLeaf Member

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    Pasco, WA
    WTF, 32 mph not in a Tesla, that's what the Leaf is for!
     
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  8. tachyon

    tachyon Member

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    Milwaukee
    MS is built to be driven
    Not to coast
    Pl enjoy your ride and stop worrying
    Life's too short to worry about KWh/mile
     
  9. CHG-ON

    CHG-ON Still in love after all these miles

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    Ahh. You're in the flat lands. I'm in the mountains of coastal CA. That really kills my energy usage. Going up, 100% draw. Going down, maybe 30% regen, if I'm lucky. But to add to that, I have this freakishly large and heavy foot that I simply do not have the strength to keep from hammering the go pedal.
     
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  10. Missile Toad

    Missile Toad Member

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    For the sake of going fast, I'm going slow. Having said that, I'm going to do a confirmation test that I can run the car down to, between 1 and 0 miles. My testing track is a local park where I've been pre-approved to use the 5 electrical outlets that are arranged around its perimeter. So, for V8.0, I'm expecting that I can run the car down to about 3 miles, and then, do the final 2 miles 'orbiting' the park while I prepare to coast in to a stop at one of the electrical outlets when I get down to 0-ish. Point of this, is to make it so I feel confident driving the car at 80-85 during a final 20 miles of reported RM. Accordingly, I will be able to reach a targeted supercharger faster, but not giving a damn about the final 5-4-3-2 rated miles as they tick off... instead of taking the car's nanny 'advice' to slow down. I'll be operating the car in fair conditions, with regeneration turned to a minimal level. I'll be bringing my dog along, just in case I need an emergency 'power boost'. (I really wish I bought a bigger dog). I'll probably do this in the next 3-5 days.
     
  11. henderrj

    henderrj Member

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    Can't wait to hear the results!
     
  12. gabeincal

    gabeincal Member

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    I regularly get 220-230Wh/mi on my S60. OP drives an S70D which is meant to be a little more economical than mine..
     
  13. gabeincal

    gabeincal Member

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    I don't think this is scientific enough. As long as you drive 80-85 in the park, maybe it is ;) But certainly not, while doing 10-15mph. Your estimates will be way off in the positive direction.
     
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  14. Max*

    Max* Autopilot != Autonomous

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    The problem with this is that you may get good results today, but next time you're out driving, your battery is unbalanced, and the rated range is an estimate. Maybe it'll underestimate a little, maybe it'll overestimate a little. You wont know until you stop short of the supercharge and have to push your car uphill for the remaining 0.5 miles ;)
     
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  15. Missile Toad

    Missile Toad Member

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    #15 Missile Toad, Oct 28, 2016
    Last edited: Oct 28, 2016
    I'm betting that what some have called the 'anti-brick' reserve also serves (to a small extent) as a 'stop at 0' reserve that makes up for any limitations in the algorithm to correctly estimate the bottom of the battery. I have not done a trip charge since Late August (and then I only went to about 98%). So my batteries are already a little unbalanced.

    One more thing. I just did a trial roll-in to the local SuperC (I don't need or want the charge), and found that from highway speeds (80MPH) to the SuperC, with a single stop over the 4 mile 'glide path' (flat, 72º temps, low wind) I was getting 142 Whr/mi. So I'm really getting those last 4 miles with 2 range miles.
     
  16. Missile Toad

    Missile Toad Member

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    OK. I had, what I'm guessing to be a 10.4 RM charge at a park near my office (10.4 since multiple checks on the charge from the Tesla app reported either 11 or 10, which it switched from time to time). I drove a route that Google maps reports is 4.4 miles flat, no wind, 72º-ish degree day. When parked in my garage, which is in the foot-hills of Mt. Krumpet (8 ft. climb), I discovered car to be reporting 2 RM (I'm going to optimistically assume it was 2.4). So the actual 4.4 mile drive (moderate 32-44 MPH) consumed the estimated (by Tesla Nav) 8 range miles. So in the 'bottom of the battery' regime, Tesla was fudging about 80% too optimistic.

    In spite of this iffy risk, I added back 2 Range Miles (RM) charging that Friday evening. In the morning, I drove back to the park (more directly) having only 4 reported RM -- but this direct route is 3.2 miles. Given the risk, I settled into a 27 mph drive (at 6:25AM), and got to the park with 1 RM reported. I drove around the park for about 0.4 mi, until I just said, "good enough". And then charged at a NEMA 5-15 outlet. I added 6 RM while I left the car parked there.

    One last thing, my 4.4 mile trip back to the house, at the beginning, had 2 stops along the way. Moral of the story, the reported RM can change, especially (because of?) minor stops for errands, during tests at the bottom of the battery. I expect that these changes are amplified if attempted at 55ºF or lower.

    I've made estimates, to the first decimal place, in imperial units. Those who use km might be able to get more fine grained reporting of the car's estimate of charge. So I'm updating my vote assuming the following conditions/stages:
    a) approaching a (super)charger at 75+ mph, and adding in RM for this kinetic energy;
    b) 56ºF
    c) no head winds
    d) flat or descending
    e) fewer than 4 full stops in the 'glide-path' to the charger, but none a stop for an errand​

    my recast vote:
    Only a madman thinks there is more than 1.0 (extra mile beyond the RM reported by Tesla Nav at stage 'a')

    Clarification
    : the poll states "...in the tank". Bear in mind, I'm still a recent escapee from ICE driving. 1) there is no tank; 2) the battery, if it can be called a tank, is not the sole reservoir of RM. In other words, the kinetic energy is assumed to be contributing to the "in the tank". Of course, all this could be moot, if Tesla re-works its RM reporting to account for the kinetic energy. This report covers V8.0.
     
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