Model 3

1000+ Wh/mi readings in early driving

edited November -1 in Model 3
Hello all,

I'm getting extremely high consumption numbers over the first few minutes of my drive. It usually regulates if I get on the highway, but I live in NYC so the highway isn't always an option.

By high energy, I mean 1000+ Wh/mi to start. That slowly (sometimes very slowly) creeps down to 500 Wh/mi, and eventually regulates to +/- 200 Wh/mi once I'm going 50mph or more. I am very aware of the factors that affect energy, and I'm not abusing any of the known culprits:

- I'm often going <30 mph, and rarely drive over 70 on the highways around NYC.
- A/C fan is usually on 2. I still get high readings when A/C is off (I've tested it all)
- I get these readings regardless of whether or not I pre-condition the cabin temp.
- I'm not accelerating in an aggressive way
- My tire pressure is perfect, approximately 48psi as recommended

I've read every forum and watched every video I could find (within reason), and I haven't seen anyone with this particular problem. A consumption surge of 1400 Wh/mi when I'm driving 20 mph with no A/C just isn't normal.

I have a two year old in the car, and I need to know that my energy readings are reliable and that my battery isn't malfunctioning in a potentially dangerous way.

No snarky comments, please. I understand the basic science of the car and the physics of driving. :)
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Comments

  • edited July 2019
    I just noticed this on Monday.......started out and was 975 wh/mi.....could nit believe my eyes....pulled over and looked at every setting....all the same from the previous day....outside temp was 70F and overcast....dont know what is happening.....have a mobile service scheduled for Thursday...will ask them
  • CSTCST
    edited November -1
    Pre-cooling the car?
  • edited July 2019
    AC load when cooling down a hot car. I see it every time I start the car in the summer. Same thing for heat in winter.
  • edited July 2019
    Normal. Small denominator issue. I’ve seen 8000 Wh/m after driving off with AC on in the driveway. Has always been the case.
  • edited July 2019
    And please don’t occupy service with a normal car
  • edited November -1
    Likely there is upward slope at the beginning, you may not notice it, but it plays a big role in energy efficiency, especially in a short period of time span you pay attention to, I suggest that you test by start in opposite direction , and read the efficacy after driving the same distance and or time to see it still give you high reading
  • edited July 2019
    Same observation on hot days, but if you go to the Energy display showing 15 mile average all is well.
  • edited July 2019
    I usually start the day about 1200 Wh/mi as I leave the 'hood but it quickly comes down to low 200's after a mile or two. Nothing to worry about.
  • edited July 2019
    It's just an artifact of starting energy divided by a small denominator. Nothing to see here.
  • edited July 2019
    Where are you seeing this? is this the energy app? If it tries to calculate it real time, yeah is pointless (i.e. what does it show in a very long down hill? like -50 Wh/mi?)

    I only use the trip computer (the one you swipe from bottom left)
  • edited November -1
    @jluis
    If you have your trip card up, you see efficiency starting at 0.1 miles into your trip.
  • edited November -1
    I use the trip meters and not the energy app. The trip meter for current trip and Last charge are the main two I use. The current trip shows the high values right out of the gate but quickly equalizes.
  • edited November -1
    Bighorn has it right. It’s watthours per mile. When you get in the car it starts using energy, but you haven’t covered any ground. By the time you get moving, you’ve used a few watthours. When you start moving you use high amounts of energy, but the display won’t show the results until you reach .1 miles. Just ignore the early readings.
    I seen it start as high as 1800wh/mile. Can’t wait to see what happens this winter using the heating.
  • edited November -1
    something something math. If 30 min in your above 400 in the Summer, I'd say there MAY be an issue. Winter will be higher so if this is your first upcoming winter, you'll see about 50-75 kw/hr higher than summer. Heat is a (relatively) big drain. I have a hill coming out of my development and I like to floor it to see how high I can get. It lasts for about 30 seconds before I come back to 220-280.
  • edited July 2019
    I see those readings when I first start with the drive of the day. Especially after pulling out of driveway and start going. I think it's simple physics here. After sitting the car is prepping the battery along with going from stop to moving which is also the point any vehicle regardless of source of energy uses the most to get car moving. But they always drop even if not leaving town speeds of 25-35 mph.
  • edited July 2019
    That's just the way it is, until it averages out over a longer distance. Regen plays a huge role to average out your wh/mile figure.

    My drive out of my subdivision is about a 1 mile drive. The wh/mile figure will be about 1000 when I get out of the house and reach the top of the hill, about 1/4 mile. By the time the road flattens out, it'll drop to about 400 after about 1/2 or so. And then comes a long downhill, and when I have 100% regen, by the time I reach the bottom, I've seen it go to a negative number, as high as -25 or so, but typically during spring and summer it'll be around 50 wh/mile by the time I get out of my subdivision.

    There's nothing wrong with your car. It's just NYC driving, with no long stretch for regen until you get to highway speeds.
  • edited November -1
    When i start my gas car, the average mpg of my trip starts out at about 3mpg as i back out of my driveway. When i get to work, its at 38mpg or higher.
  • edited July 2019
    Everything has an outsized effect in the first mile because of the short distance (small denominator), including regen. Over the course of a longer trip, not so much, including regen. Losing altitude is where gains are derived, with or without regen.
  • edited November -1
    Short distances usually have low efficiency. It takes a lot of energy to get 4000 pounds rolling in any direction, but less to maintain it once it's going. Usually, this will level out over 5-10 miles (depending on how much "stop" is in stop and go traffic).
  • You mean like this: https://drive.google.com/file/d/1bgS4Axy0GAxImlTlAr1ZJzQBzNiEA7XB/view?usp=sharing

    Just a normal day and me just trying to get out of my parking garage at work. No excessive HVAC use.

    Usually I am in the 900s but for some reason (no abnormal conditions) on this day I exceeded 2000. I thought it was interesting so I took a picture.
  • edited November -1
    Ya, thats because you traveled 0.1 miles in 4 minutes. Like everyone has been saying, when you start the numbers will be absurd. As you travel further they will even out.
  • I understand the reason for the high number. What I thought was curious about 2,333 was that I have parked in the this parking garage and usually in the same exact parking spot now approximately 350 times in my 19 months of ownership. Of those 350 times I have generally noticed about 900 Wh/mi. Well with 1 exception, which is the picture I took.

    Every time, including this 1, of course the numbers leveled out as I made the 50-75 mile drive home, depending on my chosen route.
  • edited November -1
    @charles
    Your car was on for 4 minutes before you traveled a tenth. Whatever energy you consumed in that time is factored in. A sum total of 233W, so something drawing about 3 kW. Like I’ve said, I’ve seen 8000 Wh/m after the air ran a few minutes before departure.
  • edited November -1
    Are you starting out in reverse? I see high consumption rates in reverse.
  • edited August 2019
    Perfectly normal. I get this from time to time as well when first driving, but my overall wh/mile in the summer are less than EPA even though I'm a lead-foot.
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