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Heavy head winds and needed range from Supercharger

Discussion in 'Model S: Driving Dynamics' started by Discoducky, May 31, 2016.

  1. Discoducky

    Discoducky Active Member

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    Heading to The Dalles, OR from Kennewick Supercharger requires way more range than nav thinks due to very consistent heavy head winds.

    While being towed 4 miles to he Supercharger, the driver mentioned ICE drivers also run out consistently.

    Left Kennewick with 30 buffer rated miles and experienced a consistent 30+, with gusts, head wind for nearly 100 miles along the river.
     
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  2. porshuh

    porshuh Member

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    Yeah depending on winds and rain (rain can suck a ton of power/efficiency) - I typically see efficiency levels vary anywhere between 95% all the way down to 65%. That lowest efficiency was when it was about 40 degrees out with moderate rain and wind, heat going, and elevation changes.

    When I say efficiency, I mean take how far your drove and divide by how many rated miles you lost. It's actually a really fun game (yes, I'm a nerd) to play while driving on trips. As you drive - "I've gone 120 miles but lost 140 from the rated range" (120/140 = 0.857 = 85.7% efficiency). It's surprising how good you'll get at crunching the numbers in your head the more you do it.
     
  3. BrokerDon

    BrokerDon Member

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    We got serious "range anxiety" driving in strong 30 to 50 mph headwinds to & from Primm, NV (just east of Las Vegas) and Barstow, CA a couple of months ago. Wind was so bad when we arrived in Primm, NV visibility went to zero, creating a "brown out" dust storm... It even rained mud. CRAZY. We parked our Tesla downwind behind the Primm Valley Resort & Casino to minimize our windows and paint getting "sandblasted".

    Only way we got to Primm with enough remaining battery charge was to draft a Sprinter van doing 75 mph using AutoPilot TACC distance set on 1. Worked perfectly taking us from watching our estimated remaining Tesla navigation battery charge level at Primm going DOWN towards 0% before drafting to arriving in Primm with 20% SoC. Obviously I wouldn't recommend drafting in normal driving but definitely saved the day for us on this leg of our road trip.

    To prevent weather surprises ruining your range, I suggest you use one or more of these apps which we've used road tripping in our RV to avoid high winds that could literally blow our RV off the road:

    The Weather Channel
    Weather Radio
    Windy
    WindAlert

    ... and this app is good for showing your elevation gain of your route:

    InRoute

    I hope these help.
     
  4. ReddyLeaf

    ReddyLeaf Member

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    Sorry for your predicament. Unfortunately, this area is known as one of the best windsurfing areas. The wind is almost always westerly, and for the past week we've seen consistent 25-40 mph winds. When this happens, the wind turbines are saturated, and we see 4+GW of windpower. Here's a website you can check before leaving: BPA Balancing Authority Load and Total Wind Generation
    FYI, last summer I left the Tri-Cities in my 4 yo Leaf traveling 85 mi AGAINST that same wind to the Arlington Chademo. I made it (thanks to LeafSpy, significant hypermiling, a 1-hr L2 midstream, and driving 15-20 mph uphill out of Kennewick on the parallel side road). As any bicyclist knows, wind can be fiend or friend. The return trip was much easier, even without a midstream L2 charge, due to that same 20-30 mph tailwind.

    The Tesla is much, much less affected by the wind as compared with the Leaf, but the effect is still there. It's worse with two bicycles on the back, probably at least 30% more energy consumption.

    EDIT: For those that don't know, there is a cutoff between Umatilla and Boardman through Irrigon that allows for much slower driving speeds and shortens the distances a bit. I have always taken that route, even in an ICE.
     
  5. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    If you use the trip graph and adjust your speed if the graph shows you're using too much energy, then there will be less anxiety.
     
  6. dgpcolorado

    dgpcolorado Member

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    #6 dgpcolorado, May 31, 2016
    Last edited: May 31, 2016
    That's what I did on my recent trip through the Columbia Gorge. I had first run into strong headwinds from Grand Junction CO to Green River UT and didn't slow down when I first saw the energy plot dropping. Later, I had to drive slowly at 50-55 in an 80 mph zone for many miles before I could speed up a bit when I knew from the plot I had it made. Rolled in with 3.5% (7 RM ) left. Lesson learned: when the energy plot shows something sapping energy faster than expected, slow down a bit right away until the plot stabilizes and I can figure out what is going on.

    After that experience, the next day when I hit strong winds driving from Pendleton OR to The Dalles OR, I knew to slow down sooner (mostly 59 mph according to my notes). As I got closer and knew I would make it, I was able to speed up a bit and use much of my buffer. No problems, rolled in with 4% (8 RM). I could tell the wind was strong from the whitecaps on the river; from my sailplane days I knew that it takes at least 15 mph to make whitecaps, and these were BIG ones. Knowing what I was facing, I charged to a 25% buffer at The Dalles and was able to drive at the speed limit through the Columbia Gorge (in heavy rain) to Portland with no problems.

    My rules:
    1) If energy remaining is falling faster than expected slow down right away until usage stabilizes. When nearing the destination speed up again once it is clear that I will make it.
    2) If I know I will face challenging conditions — such as wind, rain, cold or whatever — charge to a higher level to increase the buffer.
     
  7. Steve2498

    Steve2498 Member

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    If you have an 85, planning on a 30 mile or ~11% reserve seems pretty bold in that environment.
     
  8. Discoducky

    Discoducky Active Member

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    The trick was knowing about the headwind beforehand. Nav said I had enough and I've always made it prior. This was the far end of the bell curve for me after 3.5 years of supercharging .
     
  9. aesculus

    aesculus Still Trying to Figure this All Out

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    I had this happen to me last Thanksgiving week up on I80 in Nevada too. Never got my car so dirty in the rain and I had to use my windshield washers constantly.
     
  10. cpa

    cpa Member

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    +1

    (Now if Tesla could come up with a way for us mere mortals to be able to factor in the additional charge needed and recommended speed/Wh/mile for the journey before we depart with what we guess to be enough!)
     
  11. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    1. Charge till the line on the graph is all green.
    2. They do warn you that you'll need to reduces speed. I've seen less than 60 and less than 55.
     
  12. Muddy

    Muddy Member

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    Got our Model S in Dec 2014 so our first road trip was from our home near Tacoma, WA to The Dalles to show the family. On the return trip we charged to 235 and headed to Centralia which is about 165 miles. Had heavy rain and headwinds in the gorge. North of Portland we were checking Plugshare for charging opportunities. Pulled into Centralia with 7 rated miles left. Stayed for a full charge (and dinner) though we only needed about 60 miles to get home.
    On our way home from the Sound of Silence ralley last week my husband was wondering if there was a way to link a weather app with windspeed to the mileage!
     
  13. dgpcolorado

    dgpcolorado Member

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    My impression from getting those warnings — I've also seen less than 70 and less than 65 recommendations — is that they aren't low enough in wind. They seem to base the recommended speed on the remaining energy and the coming terrain. In order to stabilize my energy plot I had to go quite a bit slower than the recommended maximum speed because it doesn't seem to account for the previous higher energy drain due to strong headwinds.
     
  14. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    Right. That's why you need to watch the graph and adjust accordingly. On my trip two weeks ago, I had 20-30 mph headwinds both ways. Charging till the graph was all green actually left me with about 60 miles of range at the next SC. YMMV
     
  15. cpa

    cpa Member

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    No argument, Jerry! I left a Supercharger with 94% for a 143-mile leg. The trip graph indicated a 32% buffer. It was windy--up to 35MPH, as the flags were perpendicular to the ground and billowing. There was 1,600-feet of elevation gain. I thought I was "smart" when I started my journey at 62MPH. About 40-45 miles in I had reduced my speed from 62 to 55 to 52 to finally 48. (There was no warning--the trip graph started dropping like a stone down to 12%--and I still had > 100 miles remaining.) What I was trying to get across was that if there could be a "weather factor" built into the trip graph, I easily could have charged another 10 minutes to reach 98%, and perhaps could have started out driving at a suggested 55MPH/XYZ Wh/mile.

    I foolishly thought my substantial extra buffer and initial 8MPH under the posted speed limit would allow for the wind resistance. I was wrong. I wonder how many owners would know the proper charge level and driving speed to maintain under these circumstances?
     
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  16. RDoc

    RDoc S85D

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    As someone else mentioned, heavy rain is a real energy hog even at greatly reduced speed. We were in very heavy rain from Delaware up to NJ, generally traveling 50-55 because of poor visibility and burned over 400 wh/mi, almost a third more than our normal highway usage.
     
  17. ecarfan

    ecarfan Well-Known Member

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    I have had the same experience on a trip through there 6 months ago. I have to slow to 60 to arrive at the Supercharger with some bugger left.

    There is no question that strong headwinds and heavy rain have to be taken into account when driving an EV and that the Tesla onboard nav routing needs to be able to factor those in. That said, given the likely huge number of miles that TMC members drive, there are very few stories of people running out of battery before they reach their intended charge location.
     
  18. dgpcolorado

    dgpcolorado Member

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    Is that anything like the old joke: "We used to walk to school, uphill both ways, in the snow"?

    Definitely bad luck to face a headwind both ways on a route. At least I got a tailwind going the other way.
     

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