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Hypermiling in the P85D

Discussion in 'Model S: Driving Dynamics' started by wk057, Apr 25, 2015.

  1. wk057

    wk057 Senior Tinkerer

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    #1 wk057, Apr 25, 2015
    Last edited: Apr 25, 2015
    So, I completely forgot to post about this last week.

    When I took the P85D to the drag strip (two threads with videos here and here), I wanted to spend the least amount of time charging at my friend's place (on 240V/40A) that is ~5 miles from the strip. So, I charged to 100% at home and decided to put my somewhat rusty hypermiling skills to the test on the P85D for a ~57 mile stretch.

    Well... worked out amazingly. I averaged 254Wh/mi for the whole trip, and 212 Wh/mi for the final 30 miles. That beats my previous record from my P85 for a longer trip by a decent margin. (266Wh/mi). Range mode on, Sport acceleration, HVAC off, windows cracked.

    2015-04-17 15.12.25-1920.jpg

    2015-04-17 15.12.14-1920.jpg

    I had 81% remaining and the car was still estimating I could go 307 more miles. :D

    Partly obfuscated route (for privacy): US-321 N to Milling Rd - Google Maps

    Took about 65 minutes door to door.

    I'll have to try an even longer run next time.

    Note: EV Trip Planner says the route would be 306 Wh/mi at speed multiplier 1.0. So, I beat that by ~18% and by ~30% on the last 30 miles.
     
  2. Cottonwood

    Cottonwood Roadster#433, Model S#S37

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    See P85D Range Records for where I did 237 Wh/mi to cover 302 miles on a 99% charge with 12 rated miles left in the battery.
     
  3. bp1000

    bp1000 Member

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    Newbie question, how do you hypermile?

    Whatever you did is going to be very useful if I get caught out on range. I hope to never have to use it but it's useful to know how you do it in a tesla.

    Did you just drive very slow?
     
  4. wk057

    wk057 Senior Tinkerer

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    Not to be down on your record... but, definitely not apples to apples. Impressive record, and I wasn't trying to beat any records.

    Your 237Wh/mi trip included 227 miles from Silverthorne, CO [supercharger] to Pagosa Springs, CO with a net elevation change of -1,614 ft. Those 227 miles EV trip planner says can be done at 234Wh/mi at speed multiplier 1.0 in a P85D with 21's. At that rate you would have finished the 227 miles from a 99% change only using < 54kWh which would leave about 20kWh usable remaining, or about 62 rated miles... plenty to go the remaining ~63 miles at decent efficiency, assuming it was in the same direction, was flat, was at low speed, or included any elevation drop. Without knowing the actual destination can't say for sure, but it seems anything in ~60 miles along either road exiting Pagosa Springs, CO wouldn't have much terrain change.

    My trip, while shorter, beat EV trip planner and Tesla's in-dash estimator by a huge margin... between 18 and 30% more efficient, where you actually were ~1.2% less efficient than EV trip planner for your route.

    So, I'm not sure if your trip actually qualifies as hypermiling...

    No offense intended! Just pointing things out! *ducks*
     
  5. ra-san

    ra-san Member

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    #5 ra-san, Apr 26, 2015
    Last edited: Apr 26, 2015
    First off, wow. I'd post the smiley for eyes popping out in surprise, but I'd have to go find it. The 237 impressed me (and think it was somewhat faster speed, even if net elevation decrease), but the 212 even more so.

    By the way, ages ago when I first heard the term, I'd have sworn most called it hypermill / hypermilling not hypermile / hypermiling. Maybe I was just reading the miling part wrong and getting mill as the base. Odd, huh?

    Neither of the drove *very* slow, depending on your definition. But you aren't going to see these numbers going 75+. Wk057 had an average of ~53mph on this stretch based on his 57 miles and 65 minutes door to door, which means the biggest chunk of driving was likely ~55 or a bit higher, assuming the ends of the trip eat up a chunk of time. I recall Cottonwood's thread showing he was driving "reasonable" but not fast speeds too. Go 35-45 and you get crazy range numbers :) (check Tesla's range curve graphs on their site/blog) but that's just for records or gritting out really bad planning to get to a charger :)

    He gave some of the techniques, and I think there's additional discussion in Cottonwood's post. Do a search and you'll find way more.
    It's basically doing all you can to reduce drag and dumping energy to heat (mostly via brakes, but also by keeping power peaks down)
    Mix and match as possible and appropriate, some at your own risk:
    • Drive slow (air drag savings + power efficiency goes down as draw goes up)
    • Minimize braking (big time) and regen (still important - it's not 100% efficient). Aim for 0 power going downhill, so long as that doesn't get you too fast/
    • Minimize power peaks
    • Windows up (drag), but no climate control (resistive heating being worse, but AC/Heat pump still a load that you can remove if possible)
      (the windows cracked is suboptimal, but probably didn't add much drag and allowed him to save the load of the climate control without fogging/baking/freezing, I'd guess)
    • Drafting someone else, ideally with a bigger cross section. (reduce drag). Lots of posts on here about this and the dangers as well as potential range increases.
    • tire inflation, higher = less rolling resistance (don't overinflate unsafely)

      Things you can't always control for, but make a difference if you get lucky or choose timing well:
    • Tailwind (reduce drag) - huge benefit, just as a headwind is a huge penalty
    • temperature (cold adds load in multiple ways related to above, plus pack warming and air density. Extreme heat also affects viability of climate control being off and can increase pack cooling load, though air is somewhat less dense)
    • elevation (drag due to air density) higher is less dense
    I think that's probably in rough order too in terms of gains, from biggest gain to smallest (not counting the things at the bottom outside of usual control).

    I'm sure if I missed anything big someone will add it. Add each item has been discussed at length in other threads you can search for if you want to know more. These guys are impressive in their ability to implement these items to see the results they are getting.
     
  6. wk057

    wk057 Senior Tinkerer

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    My trip was a lot of pulse and glide. I would pick up speed significantly downhill using minimal power up to maybe 75-80 MPH, then coast (near 0 power) on flats and uphill until I bottomed out speed in the 50-mph area.
     
  7. Larry93428

    Larry93428 Member

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    Will the Valet mode, which limits acceleration and top speed, be useful to increase range?
     
  8. wk057

    wk057 Senior Tinkerer

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    Was thinking about that... but I like cruise control. I usually set cruise, but augment it with my foot when possible to gain efficiency.
     
  9. deonb

    deonb Active Member

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    What regen setting did you use?
     
  10. wk057

    wk057 Senior Tinkerer

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    Standard, but I wouldn't let the car use any regen unless needed for safety/slowing via pedal control.
     
  11. Fluke

    Fluke Member

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    Would it make sense for Tesla to include an eco mode on the P85D intended for steady-state highway driving that only used the small front motor? Not the normal intent of this model, but maybe it would help make traveling between longer distance superchargers less challenging.
     
  12. wk057

    wk057 Senior Tinkerer

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    I'm not sure using only the front motor would be the most efficient, but I do think it could use an actual "eco mode" setting for long trips where it nerfs power output a bit among other things.
     
  13. andrewket

    andrewket 2014 S P85DL, 2016 X P90DL (soon 100)

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    The car already does this, really. Range mode decreases energy consumption and optimizes torque sleep. The rest is all controlled by your right foot :)
     
  14. Khatsalano

    Khatsalano Member

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    Whenever someone does hypermiling, I have the image of Model S owners ghost riding their whips ...

    If you don't know, better recognize: Ghost riding - Wikipedia, the free encyclopedia

    - K

    PS: Elon, can I safely ghost ride my S85D by this summer with the autopilot features fully enabled?
     
  15. electrish

    electrish I Sing the Body Electric

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    You have probably a lot of experience with driving at different settings.
    My feeling is that in Range mode, Sport and Insane settings are comparable in terms of energy consumption when using cruise control, but that there is still an energy penalty in Insane mode without TACC, even when trying to drive efficiently in a P85D.
    I would assume it's because the accelerator is more sensitive in insane mode and uses the more powerful rear motor to a higher degree.
    This is why Tesla will probably always keep both Sport and Insane modes available on the P85D, whereas they removed Sport on the 85D.
     
  16. jkliu47

    jkliu47 Member

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    I have always wondered if driving with the side mirrors folded would result in a noticeable increase in efficiency. Yeah I know that's kinda risky, but the rear camera should maintain rear view visibility.
     
  17. Larry93428

    Larry93428 Member

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    Those mirrors do seem to be designed to get out of the air stream. I suspect a camera concept has been toyed with.
    .
    I too would like to see an Eco mode. Motor details would have to be up to those in the know.
    ~Larry
     
  18. ra-san

    ra-san Member

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    I would take a wild ass guess that driving with mirrors folded would not only be, to put it delicately, stupid, but would also result in more air drag, not less, given they were designed to be aerodynamic while out, not while folded, and the airflow would be unplanned and pretty ragged based on what it looks like to me.
     
  19. Andyw2100

    Andyw2100 Well-Known Member

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    Let's not forget that at last October's D announcement the cars were being shown with three driving modes, not the current (for P85Ds) two.
     

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