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AAA FUD: Winter Driving Range

Discussion in 'Model 3' started by SageBrush, Feb 7, 2019.

  1. gnuarm

    gnuarm Member

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    There are two distinct issues. One is range and the other is energy efficiency. When considering range only the distance traveled needs to be considered. When considering efficiency, the energy used to preheat the battery and cabin should be considered.

    I read a new term while reading some of the papers on this, "recharge allocation factor" This is the ratio of the energy drawn from the AC supply compared to the DC energy drawn from the battery. This is intended to be a metric of the battery and charging equipment, but in real world it should also include all other energy draw including vampire drain.
     
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  2. Eriamjh1138

    Eriamjh1138 Member

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    That’s called a “use case”. It reflects what occurs for those conditions.

    It’s unfortunate that they didn’t do a long range, single trip example.
     
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  3. Jdee2wheels

    Jdee2wheels Member

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    I have a 10 mile commute each way and below 30 degrees F, I’d say 40% reduction is about right based on my use case. I don’t have concerns about range since I have the option to charge every night, but this big reduction in efficiency was unexpected. No, range isn’t an issue, but I’m using way more electricity than I had anticipated and the savings I expected compared to using gas has definitely been reduced.

    Knowing this wouldn’t keep me from buying the car (I love this car!), but this is information people should know when thinking about buying EVs.

    I don’t think AAA did anything unreasonable given that the average commute in the US is ~16 mileage each way. That said, they could have stated that winter range is better over longer distances or tested this use case as well.
     
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  4. gnuarm

    gnuarm Member

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    I think that what people here are concerned about is that if your commute is only 16 miles each way and you charge at home, the actual range of the car is not a significant issue and so the numbers in this study are not significant. Some here have stated that they see much less reduction in range when range really matters, long trips. That really should have been studied as well rather than making up a mixture of driving patterns that don't tell you much about any of the typical use cases.
     
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  5. EinSV

    EinSV Active Member

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    #45 EinSV, Feb 10, 2019 at 2:06 AM
    Last edited: Feb 10, 2019 at 2:32 AM
    The AAA’s report is extremely misleading for the reasons others have described. I really don’t understand the efforts to defend the AAA by saying the test was accurate for the conditions tested because the AAA did not mention the limitations of the test in its press release, abstract or the study’s results, findings and conclusions. Instead it made false statements about the conclusions to be drawn from the tests.

    For example, the press release states:

    “New research from AAA reveals that when the mercury dips to 20°F and the HVAC system is used to heat the inside of the vehicle, the average driving range is decreased by 41 percent. This means for every 100 miles of combined urban/highway driving, the range at 20°F would be reduced to 59 miles. When colder temperatures hit, AAA urges electric vehicle owners to be aware of a reduction in range and the need to charge more often to minimize the chance of being stranded by a dead battery.”

    “Additionally, an electric vehicle with a compromised driving range will require charging more often, which increases the cost to operate the vehicle.”

    “‘The research clearly shows that electric vehicles thrive in more moderate climates, except the reality is most Americans live in an area where temperature fluctuates,’ said Megan McKernan, manager of Automotive Research Center.”

    Cold Weather Reduces Electric Vehicle Range | AAA NewsRoom
    These statements clearly give the false impression that the efficiency losses found in the study applied to long trips — not just the first few miles. And in the press release’s description of the study’s methods it said nothing about the study’s limitations:

    Methodology

    AAA conducted primary research in partnership with the Automotive Club of Southern California’s Automotive Research Center (ARC) in Los Angeles, California to understand impacts of ambient temperature on electric vehicle driving range with and without the use of the HVAC system. The vehicles were tested using the ARC’s climate controlled test cell and state of the art chassis dynamometer and data logging equipment.

    Test vehicles were selected using a pre-determined set of criteria such as availability for sale throughout the United States with a minimum EPA estimated driving range of 100 miles. One vehicle per manufacturer was tested to prevent overrepresentation of a single brand. Additional information on methodology can be found in the full report here.​

    While there is a link to the full study the AAA knows that busy reporters would likely just regurgitate what was in the press release, which is exactly what they did with tons of misleading articles published that parrot the misleading press release. And even if they clicked the link to the study the abstract, key findings and results all make sweeping conclusions without mentioning the limitations of the study. Even if they read the study front to back 99% of reporters would likely not pick up on its limitations.

    The AAA should have highlighted the limitations of the study or better yet performed a more meaningful study for long trips if they were going to study cold weather effects on range. They did not study effects of cold weather on range but only on efficiency for short trips (or the first few miles of a long trip.)

    Worth noting that the AAA is likely another business being disrupted by Tesla. Its membership is very likely getting hammered by Tesla’s success. With Tesla’s Roadside Service free for 4 years/50000 miles, there is little need for a AAA membership for most new Tesla owners. My fiancé cancelled her AAA membership when our second Model 3 arrived in December.
     
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  6. adaptabl

    adaptabl Member

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    Most automakers include roadside assistance with new car purchases. I am sure the majority of AAA memberships are with people who have cars outside the warranty period. Suggesting that there is a motive is wrong.
     
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  7. MentalNomad

    MentalNomad Member

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    I don't think they give the impression that this applies to Long trips. They simply gave the impression that the supplies to winter, which it does.

    They analyzed for the most common use case, which is people taking relatively short commutes and trips. You're complaining that they didn't specify that it doesn't fully apply to the unusual use case of the very long trip. That sounds a bit dishonest to me... Even on a long trip where your battery gets warm and you avoid that 12% hit, the use of HVAC, defog, and seat heaters is still going to add up... And it makes a big difference, something we need to be aware of.

    When you're done seething about AAA's report, prepare to seethe about everyone else coming to the same conclusion. It's being written about because it's a real thing.

    This article says to expect 10% to 50%, deoe Ding on exact conditions:
    Conduire une voiture électrique en hiver, c'est possible

    This article article talks about big losses on a long trip:
    Here's What Happens to Your Electric Car in a Bitter Canadian Winter

    I've seen it with my own Model 3.

    I love my Tesla. Still recommend it all the time. But I'm not going to lie about it - this is what should be expected for typical users when the weather gets this cold.
     
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  8. EinSV

    EinSV Active Member

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    #48 EinSV, Feb 11, 2019 at 4:13 PM
    Last edited: Feb 11, 2019 at 4:19 PM
    @MentalNomad

    I disagree. Even the headline of the AAA’s press release is false and not supported by their tests:

    Icy Temperatures Cut Electric Vehicle Range Nearly in Half

    No. They don’t. Icy temperatures decrease range but not by almost half. This (and the quotes cited in my post above and many others in their report) is false, misleading fear-mongering. The AAA should know better.

    If they want to report cold weather’s effects on range then the should conduct tests that measure how range is affected by cold weather.

    Their tests estimate efficiency on relatively short trips, that’s it. EVs are already far more efficient than ICE cars, so even with this drop in efficiency in cold weather they will do just fine by comparison (and ICE is less efficient in the cold as well).
     
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  9. novox77

    novox77 1.21 Gigawatts

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    Today, it was 30F. I had a 30mi round trip. After it, my car read 246Wh/mi.

    On the first leg, the efficiency was worse, because the heater was working hard to get the cabin up to temp (my set point is 72F). On the return leg, the HVAC was barely working because the cabin was up to temp.

    This same round trip in warmer temps (spring and fall) yielded me around 160Wh/mi (no HVAC). Summer with A/C, the same trip was 190Wh/mi, set point at 78F.

    I also do an 80 and 100 mile round trip for work. For both of these, in sub-freezing temps of varying amounts, I'm getting around 250-290Wh/mi, heat set at 72F. These numbers seem very acceptable to me, even if they are near double my warm weather efficiency, which admittedly are extra low cause I'm heat-tolerant and rarely use the A/C.
     
  10. MentalNomad

    MentalNomad Member

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    #50 MentalNomad, Feb 11, 2019 at 6:20 PM
    Last edited: Feb 11, 2019 at 7:09 PM
    A lot of people would call - 41% "almost half." Personally, I'd call it - 41%, but I also understand that lots people aren't like me.

    Well, yes. But that's the most common usage of a vehicle. Are you proposing that they test only for an unusual circumstance?
     
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  11. MentalNomad

    MentalNomad Member

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    54% more power used, and that's only at 30 degrees.

    Very acceptable to me, too. After all, an ICE engine heats the cabin with "waste heat." But I'm more willing than most to try to save on waste - I also have the 2000 Honda Insight I bought, new.

    I agree with you, but a lot of people would be very unhappy with that sort of decline if they weren't expecting it; pretending it doesn't happen doesn't serve the public.
     
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  12. EinSV

    EinSV Active Member

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    "Range" means how far the car can drive on a full battery. AAA did not measure "range" they measured how many kWh were used for a short commute. Two completely different things, as many people on this thread have pointed out multiple times.

    And you seem to acknowledge they are two different things.

    If the AAA wanted to measure how far the vehicle will drive on a full battery they needed to do a different test. They didn't but yet they report that EV range is reduced by nearly half, which is totally misleading and not supported by their tests.

    And to make matters worse, the inaccuracies from the press release were parroted by the press so people not familiar with EVs who listen to the news reports have an exaggerated idea of how much range is lost in cold weather.

    It's not that big of a deal to use more battery on a short commute because most people charge at home every night and wake up with a full charge.
     
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  13. MentalNomad

    MentalNomad Member

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    Ah, maybe this is the root of our misunderstanding... I suspect you think "range" means how far the car can drive on one continuous trip with a full battery - but it isn't.

    A battery that can put out ten 30-mile trips before charging has a 300 mile range. Whether I do two 150-mile trips or thirty 10-mile trips, I've gotten 300 miles of range. (And the same is true of the mileage I'd get out of a gas tank on an ICE, too.)

    They are two different kinds of driving that typically get the same range out of a battery. Range is how far it can go on one charge, period... not how far it can go on one charge in one non-stop trip.

    The US stats say that 80% of commutes are 20 miles or less, and 50% are 10 miles or less. (Only about 5% of commutes are more than 40 miles.) That's a lot of short trips. AAA is measuring for the kind of driving that most of us do.

    Yes, if they want to test for "long road trip" mileage, they'll have to do that separately, but that's not likely, because they test for typical usage.
     
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  14. gnuarm

    gnuarm Member

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    I think the point is that this is not terribly relevant in the context of being concerned about range.

    I don't think the tested use case of "combined urban/highway driving" is one where people particularly care about range because they seldom need the full range available whether or not the temperatures are extreme. An exception to this is for owners of cars with very short ranges like the BMW i3. The times when longer range is needed would be virtually all highway which was not tested and would most likely result in significantly less range reduction. We may never know for sure since it is unlikely an independent source will perform this test... at least, not any time soon. Maybe Consumers Reports will release more useful test results.

    BTW, tonight I had my first opportunity to use Tesla a destination charger that wasn't as a poor substitute for trip Superchargers. We went to dinner at a restaurant which had three destination chargers and it looks like a Cripple Creek unit. An ICE auto was parked in one slot because the lot was pretty packed. I wasn't terribly pleased with the food, but I was very happy to have over 20% more charge on the car when we left than when we came in. With the cold temps and the local short trips I was getting concerned about getting back to a Supercharger driving south on the highway tomorrow.

    Wait, did I just describe the scenario AAA tested for? Opps!
     
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  15. EinSV

    EinSV Active Member

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    #55 EinSV, Feb 11, 2019 at 9:42 PM
    Last edited: Feb 11, 2019 at 9:49 PM
    @MentalNomad — I think we are going in circles and will have to agree to disagree. Any halfway decent study reports its limitations. The AAA study did not and the public is being misled as a result of their shoddy work. Another piece of FUD to confuse someone considering switching to an EV.
     
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  16. McFlurri

    McFlurri Member

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    My personal experience is a significant reduction of range. Hell in just 2 hours of my model 3 completing charging i lost 19km of range!

    Honestly my consumption has doubled from the summer.

    I totally expected this and am not complaining. This isn't FUD. I understand this is the Tesla Fanboy website (im a self appointed fanboy too), but not every negative story about Tesla and EVs are FUD.
     
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  17. SageBrush

    SageBrush 2018: Drain the Sewer

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    I don't care about my car's range because of my daily commute, I care about it because I also use the car for long trips.
    The FUD was describing their 'use case' as a range test.

    The EPA has a couple different test cycles, in your lingo a couple of different use cases. The one EPA calls a range test is a single long drive that uses the entire battery without cold soaks during the drive. AAA should have done the same but instead devised a convoluted commuting test and sent it out to the echo chamber as EV winter range FUD.
     
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  18. sjg98

    sjg98 Member

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    I think calling this FUD is being hugely unfair to AAA.
    It aligns with experience I've had on short and medium range trips for sure.

    My recent experience in ~30F cold soaked car. [long, skip to SUMMARY for short math]
    Start with 180mi & snowflake icon, to drive 50mi, stay for 4 hours and turn back 50mi.
    100mi drive should had 80mi on return.. or maybe ~90-100mi since I had snowflake.
    Instead, had 50mi remaining (not 80-100mi) & warning my car would have much less range left if not immediately charged.
    Next morning.. 35mi and snowflake... drove 1mi and now I'm down to 32mi and snowflake.

    Urban Supercharger @ William Vale is valet only.. I tracked progress in app while at gym.
    1 hour at charger and I see them move the car a few times, charging start/stop a few times.. etc.. no range increase.
    Gave them a call and they said they couldn't get charging to start.
    Error lights on charging port, etc. Tried me on both chargers, was working on other Teslas just not mine.

    Pickup car to find it with 29mi & snowflake.. but full regen.. which makes me think the charger heated my battery up but was reporting status poorly on screen/app.
    Decide to drive to next nearest Urban Supercharger @ Brooklyn Museum I can plug myself into ~5 miles off.
    At this point I'm thinking if my port really is broken I have just enough range to drive to Red Hook service center before I'm dead on the road.

    I got to Brooklyn Museum with about 25mi range, plug in and get ~50kW charge rate through to about 60-70% or so when it dropped to 35kW.

    SUMMARY
    106mi in under 24hrs (50/50/1/5 mi drives) of driving
    Consumed 155mi of range (plus some ambiguity of snowflaked range)
    Failure to charge scare (possibly too cold to charge and/or bad charger plug, incompetent valets, etc)
    Then a 70% charge rate
    Blew my whole morning trying to avoid a dead battery before the snow storm.
     
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  19. gnuarm

    gnuarm Member

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    I calculate a 32% range reduction which is nothing close to 50% which was the AAA headline, no?

    I agree that the headline was FUD on two counts, the tests were not appropriate for considering range and 41% is not so close to 50% in this context.

    Your case was a real anomaly because of the valet parking preventing you from actually seeing the problem which may have been fixable and then the error itself which is not a normal part of the range issue. Had it not been for the charging problem you would not even be reporting this day.

    I think the real story in your report is the importance of having charging where you live or stay. I've learned that lesson. Just having access to a destination charger during dinner last night made a big difference in my confidence reaching a Supercharger today.
     
  20. McFlurri

    McFlurri Member

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    #60 McFlurri, Feb 12, 2019 at 7:57 AM
    Last edited: Feb 12, 2019 at 8:03 AM
    I would absolutely call 41% close to 50%. To each their own i guess but come on people. This is an "issue" for many many people.

    The mass market expects a similar experience to what they have become accustomed to with ICE vehicles.

    Im sorry, but i have never owned an ICE vehicle that effectively had a leaky fuel tank, by design.

    Everyone here is right. 99% of the population does not need the 500km range. But that means that this (cold-gate??) "Issue", affects a large group. If we are all doing relatively short trips, then the percieved range loss is more than those who try to do a Bjorn Nyland range test all in one go.

    When you fill your gas tank then take your car home, does it lose more than 27km in less than 8 hours? Cause my model 3 does (because of science i know.. but you have to get my point..)

    As i have said before, i am not upset or surprised by this as i knew whay i was getting myself in to. But seriously.. look at it from the perspective of the masses.
     
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