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Is Model X's efficiency really this bad?

Discussion in 'Model X: Driving Dynamics' started by wk057, Mar 23, 2017.

  1. wk057

    wk057 Senior Tinkerer

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    #1 wk057, Mar 23, 2017
    Last edited: Mar 23, 2017
    Greetings!

    So, I just finished a ~2600 mile road trip in my X P100D, mostly up and down I-95 on the east coast. I went from my home in NC to Orlando, FL, back home, then to NJ, then home again, plus some in-town driving at each place.

    Three people plus a minor amount of luggage... nothing too crazy. No trailer or anything either. Weather was very good for all but the first day of the trip where it was colder (~40F) with a little bit of rain here and there. Other than that was generally between 55F and 80F with clear skies.

    The majority of the trip was done with range mode on, sport mode acceleration profile (ie, ludicrous disabled). Normal highway speeds ranging from ~55 to ~75 MPH.

    My trip meter since leaving home:
    [​IMG]

    Now, a rated mile in the X P100D, according to the car, is 342 Wh/mi... however I've never been able to hit this in practice under normal conditions. But 460/342 = 134.5% of rated energy usage.... which seems a bit excessive to me.

    I tried twice on Florida afternoons when it was ~70F on flat roads to cruise at a steady 65 MPH with the HVAC off to see if this made any difference in efficiency. The best I was able to get over a 15 mile stretch was about 380 Wh/mi... and I'm pretty sure some of that gain was tail wind.

    The trip planner was also consistently wrong about the amount of energy needed to reach the next charger, usually by roughly 10%. I would charge until it said maybe 15% charge at my destination, start driving, and 10 miles down the road it'd have adjusted to 4-5% and complain about "Drive 60 MPH to reach your destination" or whatever...

    I also had a script I made running on the CID monitoring HVAC power usage at times. Last time I complained to Tesla about power usage they blamed it on the X having two PTC heaters and the winter cold at the time (December). However, even on the coldest part of the drive, where both PTC heaters were running for a bit to hold ~68F inside, HVAC power usage only accounted for about 6% of total consumption... not enough to account for the huge difference vs rated efficiency.

    Now, admittedly, this is the only X I've driven longer distances with. I've driven tens of thousands of miles in the S's, however, and even with a very lead foot I would maybe get 20% usage over rated... but usually around 10% over rated efficiency when driving normally with traffic. With the X, even when I'm trying to drive conservatively with the flow of traffic I can't get anywhere near rated... heck, +20% would even be great.

    Long story short, I'm trying to see what others get under normal conditions in their X's. Preferably some numbers from P variant longer trips. I've noted my numbers to Tesla and have an appointment scheduled for next week. Would be great to have some data that helps confirm I'm not crazy and that my car is abnormally inefficient. I'd figure if this were normal for the X there would be more outrage, but I haven't really seen any... which leads me to believe it's just something with my car. Random note: They recently did an alignment and 4-wheel balance on my X before my trip.

    My X charges to 289 rated miles with the 100 pack... however charging to near 100% and heading out I can barely do 200 real miles still, which is disappointing. Also, the 100 pack maintains higher power levels during supercharging vs the 85/90 packs, but most of that benefit seems to be negated for me since the car is using 35% more energy than it should be... so I still ended up needing to spend a lot of time at chargers in the taper area of the curve when I feel like that shouldn't have been needed at all with the larger pack. I estimate I spent a good 3 hours extra at superchargers through the whole trip because of the inefficiency vs expected.

    Anyway, aside from this and the Columbia, SC supercharger being 100% ICEd when I got there, this road trip was still fun, but would like the next one to be better if possible.
     
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  2. vandacca

    vandacca ReActive Member

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    #2 vandacca, Mar 23, 2017
    Last edited: Mar 23, 2017
    I have recently completed a long ~1200 mile trip (with a hitch-mounted tray carrying 4 snowboards in a water-tight carrier bag) and I have three data points to add.
    1.) I too noticed that after leaving a SuperCharger, the estimated arrival charge would immediately drop significantly after driving ~10 miles. However, it slowly creeped back up a little during the trip. For example, it would start at arriving with 20%, drop to 13% and then slowly make it's way back to 16%.

    2.) My 90% is 225 miles (P90D). Currently have Tesla 19" Cyclones with winter tires.

    3.) I was struggling to keep under 480 Wh/mile in -12ºC (~10ºF).

    I didn't bother collecting more exact trip statistics for my first long-distance trip. I just dynamically adjusted my speed based on my estimated arrival SOC. I simply slowed down till the arrival SOC would stabilize around 10%-15%. On one stretch, it got down to 6% before creeping back up a little. I noticed my wife got very quiet during this time, and she would regularly glance over at the trip display.
     
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  3. SM18

    SM18 Member

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    Do you have the bigger wheels? There have been posts about how they limit range.
     
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  4. Bishop

    Bishop Member

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    I have a 75D with normal tires and my 90% is 212 miles I'll double check my mi/wh but i want to say it was 363 but i dont even try to do better i just drive.

    also wk you get iced in columbia lemme know I have a charger that reaches my driveway and im right up the road
     
  5. neverdone

    neverdone Member

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    X P90D; 20inch tires; 19356 miles, 382 Wh/mi
    My wife and I just got back from a 2774 mile road trip from Loveland, CO to Homer, LA; 430 Wh/mi.
    I do the speed limit; or 5mph under when battery percentage keeps dropping.
    Temperature was moderate, 60-70F; no mountain driving; but some high winds (we did some drafting to decrease Wh/mi).
    We usually charge to 15% more than the tesla Trip estimate.
     
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  6. LoL Rick

    LoL Rick Like Buttah

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    I had an X P100D with 20" wheels and 5 seat configuration for an extended test drive over the weekend. The best I could do over a 15 mile stretch was 337 Wh/mi. AC was on but set pretty much equal to outside temp. That was when I was deliberately trying to see how efficient it could be. Over 400 Wh/mi was typical, even when I wasn't stepping into the power.

    On the other hand, a similar stretch in my Model S 85 (rear drive), with a couple bursts of acceleration, would be well under 300.
     
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  7. bak_phy

    bak_phy Member

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    I've been hitting something like 450Wh/mi as well on longish trips, which is disappointing. I currently have 19in snow tires. I think that the lifetime usage is significantly above that but the car mostly does short drives in a hilly area.

    I've found that the Tesla trip planner is pretty accurate after it's re-calibrated itself to my driving. This usually takes just a few minutes. At that point it creates the colored line which is much more accurate than the grey line. What really gets me though is that after I stop to charge it goes back to assuming that I'll be driving on the "grey line" and so gives me an extremely incorrect estimate of how much I need to charge to reach my destination when it definitely knows better.

    Edit. Its a P90DL
     
  8. andrewket

    andrewket Well-Known Member

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    Turning off Lud mode won't help you, unless you're regularly stomping on the accelerator, and with 3 passengers and luggage on a trip I'm guessing you were taking it easy. Range mode will help some under certain conditions on the highway, but not a ton.

    As others have said, if you've got the 22" wheels, you're paying a huge penalty of 10-15%. The EPA ratings are with 20's. Also, the performance tires are sticky which increases drag. LRR tires will increase efficiency. Also don't forget the XP100D is the heaviest Tesla in the current lineup.

    Outside of temps, speed is really the only other major factor. Energy requirements go up expedentially. A change of 5mph makes a difference.

    Our X isn't currently at home so I can't look at our currrnt average. My guess is it's around 390-400.
     
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  9. martinicus

    martinicus Member

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    We just took our first trip with our X 60D (20" wheels) from NJ to Poconos, and our efficiency numbers were in the low 300's even with cold weather on the way back. On the way there, uphill, 50 degrees, avg. speed 46, avg efficiency 332 wh/mile. On the way back, temp 21 degrees, downhill, avg. speed 53, got 322 wh/mile. I was driving pretty gently, not a ton of high speeds.
     
  10. Cellsaver

    Cellsaver Member

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    Model X P90DL w/ 22" wheels here, same issue. I know, wheels, cold, speed, all reduce range. But the system should at least be smart enough to account for this so that as soon as I leave the supercharger and get back on the highway I get I warning that I won't reach the next supercharger unless I drive like my grandma. Actually more like my great-grandma, probly in her Model T.

    TC
     
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  11. David29

    David29 Member

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    How are you able to run a script or any code on the Tesla display?
     
  12. ohmman

    ohmman Maximum Plaid Member

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    My lifetime consumption on our X90D w/20" wheels is 338Wh/mi, and that includes some towing. On highway trips, I seem to hit around 340-350Wh/mi depending on speed.

    It's a bit of a hungry beast.
     
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  13. randy1077

    randy1077 Model X60 Vin 180XX. Reverved 8/11/2016

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    On a 1000 mile trip from Dallas to Ohio over Christmas,I averaged 345 WpM going 70 ~75 MPH with 4 people and a hitch mounted luggage rack. Heater was mostly off and Range mode on with Very Low suspension setting. 20" Wheels, X60D.
     
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  14. Phil Seastrand

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    I've achieved ~340 wh/mile in my 90D with 20" wheels in my 12,000 miles of driving. This included a 4800 mile drive roundtrip from California to North Dakota. My experience shows driving 65 MPH on a flat highway with no heater or AC I can easily average 300-320 wh/mile and with AC (or heat) it only rises to around 340 wh/mile. The only time I see >400 wh/mile is driving around town in cold weather with frequent stops where I have to re-heat the batteries and/or the cabin with each new segment.
     
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  15. Hans Allis

    Hans Allis Member

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    He's batman... No, seriously, when it comes to tinkering with Teslas, this guy is as close to batman as you can get.
     
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  16. goneskiian

    goneskiian Active Member

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    I'm going to assume you've got the 22" wheels. Even then, 460 seems really high for moderate temperatures and moderate elevation gain/loss.

    I've been tracking the lifetime average Wh/m folks have been reporting here in various threads so thanks for the data. Here's the google doc. Yes, it started as a tracker from the "What's your 90%" thread so that's why that data is in there. There are too many tire combinations to track that but I have been trying to track the wheel size too. Unfortunately that's kinda tough too with folks (like myself) switching between different wheels for winter and summer use. Although, as I've said before, I may just stay on the 20's from here on out since they really do make a difference. At least until I decide to pony up for some really expensive lightweight 22's.

    What's your 90% and Lifetime Wh/m
     
  17. idoco

    idoco Member

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    90D (not P). 20" wheels. Mileage below includes both all season and snow tires.

    9457 miles
    3014.5 kWH
    319 Wh/mi
     
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  18. Gwgan

    Gwgan Almost a wagon

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    "Three people…" Did you have the rear HVAC on? I found when outside temp is below freezing I'll see 450-500wh/mi with rear heat going but As low as 350-385ish with it off (when regen is not limited). I've seen below 325Wh/mi in warmer temps with AC at full speed highway driving too so battery temp must be a dominant factor.
     
  19. Saghost

    Saghost Active Member

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    My X75D on 20" LRR tires is about as different as an X gets, but for what it's worth, in good weather I generally find it easy to stay below my 308 Wh/mile EPA rating below ~65 mph. Not surprisingly, the X doesn't respond well to high speeds, and 75+ can get ugly, especially in the cold.

    Even with a lot of ~70 mph road trips and mostly freezing winter miles, over the last 7 months and 12k miles, my lifetime is 340 Wh/mile according to the car.
     
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  20. X Fan

    X Fan Supporting Member

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    #20 X Fan, Mar 23, 2017
    Last edited: Mar 23, 2017
    trip North.png trip.png

    Stats from 700+ mile trip this week from Naples-Charlotte back to Naples...very cold, up to 15mph wind going North, no rain, 5-8mph winds South....

    btw: a plug for TeslaFi....fantastic app that allows you to track everything. I've been able to fine tune my trips up/down East Coast through statistical analysis.

    [/ATTACH]
     
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