Efficiency hits — AWD & Off Road.

Aptera Community Aptera Discussions Efficiency hits — AWD & Off Road.

Aptera Community Aptera Discussions Efficiency hits — AWD & Off Road.

  • Efficiency hits — AWD & Off Road.

     James Castaneda updated 3 weeks ago 14 Members · 32 Posts
  • Clint Nichols Nichols

    Member
    April 26, 2022 at 9:21 am

    Do we know when there will be official numbers on the impact the AWD and Off Road Package will have on range? I’ve modified my preorder a couple of times now but I’m still very unsure what to go with. I now have all the solar panels, in a 400kw package. I live in Northern PA so we get snow here in the winter, and I am in a very rural area with the occasional dirt-driveway, and regular pothole-litered roads. I feel I should go with the AWD and ORP, but if that’s going to kill the efficiency to the point where I regularly have to charge it I’d rather do without and just drive my truck on a days with snow or trips into the back country. Does anyone have any thoughts or knowledge here? I’ve been digging through discussion posts and it seems like I’m not the only one confused on this point.

  • Jonathan Reni

    Member
    April 26, 2022 at 9:40 am

    As of right now, there isnt a lot of clarity on what the ORP is. It seems to primarily include wheel pants with greater clearance. They will impact efficiency but propbably not too significantly. If the tires were changed, that might be a more significant concern for efficiency. If it were me, i would definitely get the 3 motor configuration. I would probably also get the standard wheel pants. Worst case scenario, you may just need to remove the wheel pants if the snow is too deep.

  • Len Nowak

    Moderator
    April 26, 2022 at 9:55 am

    Yes… many replies in threads and the FAQ spreadsheet

    I am personally planning on NMT 10% loss on the AWD and hope the ORP ends up just to be a change out of the covers for about two additional inches of GC, so minimal range impact

    My Off Road is nothing more than primitive roads to get to birding/ hiking start points.

    Aptera can be AWD but not all terrain trekking.

    Everyone has their own needs

    I plan cross country/ long treks. So 60 kWh is my plan and while national EV charging is still not where I like it!

    For battery health… I plan to never exceed 80 % charge unless a stretch requires the safety of occasional 100% ….until the Aptera manual suggests something different

    Surely 40 kWh will be popular for most!

    My personal early notions

    ¯\_(ツ)_/¯

    • Clint Nichols Nichols

      Member
      April 26, 2022 at 3:13 pm

      Thanks Leonard. I just looked through the FAQ page again and still can’t find a reference to the efficiency loss of the AWD, but that sounds like a good number to go by. I’m going to stick with the full solar package, I’ve removed the ORP and I’m still on the fence on the AWD. I’m at a loss for your NMT abbreviation :-/ I feel like it should be obvious, but I can’t get it 😛

      • kerbe2705

        Member
        April 26, 2022 at 10:39 pm

        Len’s “NMT” means “no more than”…

        You won’t find the 10% figure (range hit for AWD) in the FAQ – it was mentioned by Chris during one of the webinars given for Ambassadors.

        I’m going with AWD for two reasons: We have amazingly sudden “flash flood” downpours here in the deep south that can dump 2-3″ of water on the road in front of you within a matter of minutes and, also, the occasional ice storm – but mostly because I drive from Mississippi to the Poconos every year to visit friends and family. I know what it’s like to drive the not-well-plowed Northeast Extension and to crawl over the Blue Mountain on 309 and 100 in the snow!

        • Clint Nichols Nichols

          Member
          April 27, 2022 at 4:10 am

          Thanks Kerbe2705! In my head I was trying to translate that into an option that wasn’t going to cause more than 10% loss. To many acronyms… AWD, ORP… Was pretty sure it wasn’t something like non-metal-tires. LOL. I’m pretty sure I will end up with the AWD package too. Will wait and see how long that adds to the wait-time.

  • Francis Giroux

    Member
    April 26, 2022 at 10:52 am

    I will bet that the Aptera is certainly better in snow than any pickup truck with two wheel drive. I see no reason for AWD except for drag racing. I see no reason for off road package unless you are planning on rock climbing, not just dirt roads. I understand the plan to charge only to 80% except for trips. I’m 100 miles from the Canadian border in New York state and get plenty of snow, but I don’t plan on any special tires for the winter than what comes on the car. In fact if anything I may want to buy some second hand, half worn out, narrower tires for real efficiency. My 2000 Honda Insight (same weight as Aptera) uses five inch wide tires and Aptera comes with eight inches wide. Of course I will do some testing and report the results.

    • John Malcom

      Member
      April 26, 2022 at 11:05 am

      Obviously not intimidated by the boogeyman of winter driving in an Aptera. Also sounds like your confidence comes from experience driving in winter conditions. We will all look forward to the report of your Aptera observations. I am especially interested in the results of skinny tires. I had a fist gen Insight. The right ties on that car made a big difference in MPG. Loved that car! One of the things that motivated my interest in the Aptera.

      • Francis Giroux

        Member
        April 26, 2022 at 7:29 pm

        John, you and myself are the two that I referenced in another post that still drive the Insight. I guess its just me now. What’s the best mileage you ever got with yours. I bought my second one with 140,000 miles on it when it had something like 47.5 mpg lifetime average. Now it has 204,000 miles on it with a 55.4 mpg average. If you do the math I had to get 87 mpg average during those 64000 mile I have driven it. According to my memory over the four years I have achieved over 80 mpg many times but I don’t think 87 mpg average is quite right. Greta car though, no air conditioning and my drivers window stays up because the electric window motor quit working long ago. Upstate New York is not too hot. I drove my Porsche 914 in Phoenix in 1974 with no air conditioning. 115 degrees once I think.

    • kerbe2705

      Member
      April 26, 2022 at 10:43 pm

      If you’re driving Aptera on snow-covered, un-plowed roads – following in the tracks of 4-wheeled vehicles, your rear wheel is going to be dragged through the slush, ice and snow piled in the middle of the lane: This might make AWD more necessary than you imagine.

      I spent a number of years living in Upstate and I always changed my vehicle from all-weather to snow tires for the winter – even when they were AWD.

      • Curtis Cibinel

        Member
        April 26, 2022 at 11:24 pm

        On the plus if you are AWD that rear tire will have traction. Snow beyond the main body height is rare and less significant than normal cars.
        PS: I live in BC; Canada-light for tough weather. 🇨🇦

  • Elias Fowler

    Member
    April 26, 2022 at 8:35 pm

    It would be really handy if the “off-road” wheel pants (assuming they are just removable pieces) fit inside the drop storage inside the trunk. Then you wouldn’t need to leave them rattling around somewhere while you’re bumping around dirt roads.

  • Gregory Matwiejow

    Member
    April 27, 2022 at 2:32 pm

    If all 3 motors use the same power, the AWD will increase power usage by 50%. That would bring the 400 mile range battery down to 266 miles. So if this is accurate, if you want 400 miles or range, you’d need the 600 range batter for AWD.

    Maybe the team have worked out a way to improve that efficiency, but considering the improvement the AWD upgrade makes in acceleration. I wouldn’t expect it to be too far off from this worst case.

    We’ll see. Hopefully my ignorance is on full display here.

    • Jonathan Reni

      Member
      April 27, 2022 at 2:58 pm

      Gregory,

      I don’t see how the two front motors will continue to work as hard if they have another motor pushing them from behind. In an apples to apples acceleration and load comparison, you would definitely expect a loss in efficiency, but not nearly as much as that of an entire motor. All motors will work together, lessening the strain on any single motor, but increasing somewhat the total power used across all 3.

    • Curtis Cibinel

      Member
      April 27, 2022 at 3:22 pm

      The AWD can get enough power from the ~25KW version to fully power all 3 motors but when maintaining a constant speed you arent using a tiny fraction of even 2 motors full power. Because the motors are permanent magnet and cant be shut off their is a efficiency hit but it isn’t 33%. They have said it will be around 10%. This incidentally is around the hit of AWD vs FWD in models with both options.

      So lets say we have the 400 mile version, lose 40 miles from AWD, another 40 miles from offroad wheel pants, 50 from driving 72 mph instead of 60 mph, and 20-50 for heat/cooling/stereo. Now you are looking at 220-250 miles of range rather than 400. Still reasonable but these real world factors are why I (and I suspect many) chose the 400 mile version instead of the base.

    • Joshua Rosen

      Member
      April 27, 2022 at 3:29 pm

      The power used is the power required to perform the task at hand. If you are cruising along on the highway you have to overcome the resistance of the air and the rolling resistance of the car. The third motor has zero impact on the aerodynamics of the car but adds a small amount of weight which will increase the rolling resistance slightly, very slightly. If the power required to do that is X then if you have two motors then each motor has to contribute X/2 and if you have three motors each has to contribute X/3. The motors in the AWD will be running slightly cooler than the motors in the FWD which means that the resistance of the windings will be slightly lower which means that the i^2R losses will also be slightly slower. When accelerating the extra weight of the third motor will increase the energy used but not nearly as much as a bigger battery or a second passenger will. The only time you will see a big increase in the instantaneous power used is if you floor the accelerator. The AWD will do 0-60 in 3.5 seconds while the RWD will do it in 5 seconds or so, to get to 60 in 3.5 seconds takes more power. However if you drive like a sane person and do 0-60 in 8 seconds the power used will be the same for either setup.

    • Clint Nichols Nichols

      Member
      April 27, 2022 at 3:29 pm

      Well now I feel dumb. The answer was staring me in the face all this time. The two options are 100kw or 150kw(AWD). The FWD is 100kw and on a 400kw battery that will lend you a 400 mile range. The AWD is 150kw and on a 400kw battery that will lend you a 266 range as you stated. Take that a step further the solar cells charge 4kw in a day, or 40 miles gained in a day. If you have the AWD however you will only gain 26 miles in a day on that same 4kw charge. I guess that answers my question! My average daily commute isn’t all that much, but I would hate to take that big a hit on efficiency just to be able to ‘smoke’ practically any car on the road (pun intended).

      • Peter Jorgensen

        Member
        April 28, 2022 at 8:46 am

        That’s not how power and capacity works…

        The battery is 400 kwh – Kilowatt-hours.

        The motor’s peak power is 100 or 150 kw – Kilowatts.

        That doesn’t mean that’s how much power it uses all the time, that’s only when you floor it.

        If you have a 400 kwh battery pack and you somehow floored it until the battery died, it would run out in 4 hours with FWD and 2.6 hours with AWD.

        When just driving along, the FWD version will use about 10kw and the AWD version would use about 11kw to keep rolling along at highway speeds. Unless you step on it then it can go up to 100 or 150 kw for a few seconds.

        The solar produces 700W or 0.7KW of power (max). In a day this produces about 4 KWH of energy because it doesn’t work at full energy all the time. If you go 10 miles for each kilowatt-hour (kwh) that’s 40 miles.

        Kilowatt – KW : Power, like horsepower

        Kilowatt-hour – KWH : Energy stored, like gallons of gasoline.

        Running a motor at 1kw for 5 hours consumes 5 kwh. Running a motor at 3kw for 1 hour consumes 3 kwh, etc.

        • Clint Nichols Nichols

          Member
          April 28, 2022 at 7:18 pm

          Thanks Peter, that was a great explanation. I kind of started thinking like that too right after I replied. But kept my mouth shut because I knew someone would explain it much better. (Cunningham’s law). I’m hoping that the designers/engineers will provide better estimations as we get closer to the actual production date. Perhaps even actual real-world-tested-results.

          • Peter Jorgensen

            Member
            April 29, 2022 at 7:07 am

            I just realized I made a mistake – The battery is 40kwh not 400 kwh. So it would run out in 0.4 hours if you floored it. I need to sleep. LOL

        • Joshua Rosen

          Member
          April 29, 2022 at 7:29 am

          I don’t believe there will be a 10% difference in efficiency between the FWD and the AWD, it’s likely to be about the same. The Tesla Model 3 RWD has an MPGe of 132, the AWD is 131. For city driving it’s 138 vs 134 but the AWD M3 is 600lbs heavier than the RWD. Tesla puts a smaller battery into the RWD which accounts for most of the weight difference. Aptera keeps the battery size independent of the number of motors so the difference between AWD and RWD is likely to only be 50-100lbs. Battery size will make the big difference in city driving efficiency for Aptera because there is such a wide range of battery sizes. On the highway weight is much less important as long as you are driving at a steady speed, for the Model 3 both the RWD and the AWD have an MPGe of 126.

          My guess is that if they’ve said AWD is 10% worse than RWD that’s just to cover their asses, it’s better to under promise and over deliver. When the final numbers are measured I’d lay odds that the efficiency hit for AWD will be very small.

          • Curtis Cibinel

            Member
            April 29, 2022 at 9:53 am

            Tesla is different because they use non-permanent magnet motors which can be disengaged for their AWD options. Chris did say 10% in a interview about a year ago but hopefully it will be a bit less.

            • Joshua Rosen

              Member
              April 29, 2022 at 10:03 am

              Could someone explain why a third motor would decrease the efficiency aside from the extra weight? Electric motors have a flat power curve unlike ICEs, running three motors at a time just reduces the power put out by each motor. When doing regen the third motor should increase the energy recaptured in that you’ll get more powerful regen braking which will reduce the reliance on the friction brakes. Obviously there is something I’m missing. You are correct in pointing out that one of the motors in a Tesla is an induction motor (the front motor) not a permanent magnet motor (the rear motor in a Tesla) and that they disengage it except when the extra power is needed so there must be a reason that they do this. I’m not a motor guy, I’m a digital engineer which means that I can count to 1, what’s the explanation?

            • Francis Giroux

              Member
              April 29, 2022 at 4:02 pm

              Electric motors also have efficiency losses caused by seals and circulation of coolant as well as efficiency loss from the inverter. Plus when cruising, using three motors to put out the power that could have been put out by two motors, causes the motors to operate at lower torque setting where they are not as efficiency. Study the efficiency graphs vs torque and rpm from the Elaphe video and you will see the better efficiencies are at higher than minimal torque. I agree that the loss of efficiency using three motors versus using two motors is certainly not 10%, likely closer to 1-2%, but there is a loss. Know you know where that loss comes from.

  • Qiang Fu

    Member
    May 20, 2022 at 1:29 pm

    If Aptera can be tuned to be driven with single rear wheel in most of the road conditions, I would argue AWD may be able to achieve even longer range than FWD…

    • Joshua Rosen

      Member
      May 20, 2022 at 1:55 pm

      Aptera uses three permanent magnet motors, you can’t disengage permanent magnet motors without a clutch and that adds complexity and reduces efficiency. Tesla uses one induction motor and one permanent magnet motor, the induction motor is only used when then need extra power or they need 4WD, normally they just drive the permanent magnet motor.

      • Qiang Fu

        Member
        May 20, 2022 at 3:52 pm

        I see. I guess there’s a tradeoff that engineers will have to work out between added complexity and the efficiency gain from one wheel drive. From what I read, Polaris Slingshot is a one wheel RWD.

        • Qiang Fu

          Member
          May 20, 2022 at 4:01 pm

          Or maybe we can have three versions of Aptera to choose from: FWD only, RWD only, and AWD. I bet RWD will probably win the range test..

          • Curtis Cibinel

            Member
            May 20, 2022 at 4:51 pm

            Adding varient adds cost due to r and d. Also RWD would terrible on ice, snow, or offroad; maybe it has a niche use case long term but likely getting a family car to market will trump that priority. Efficiency at complete exclusion of practicality isn’t great – they would make a solar race car.

            • Qiang Fu

              Member
              May 20, 2022 at 6:57 pm

              Agree. Driving a single wheel RWD on ice/snow/offroad would be a very bad idea.

            • Riley ________________________________

              Member
              May 21, 2022 at 4:13 am

              a rear wheel only aptera wont add any complexity. If I order an all wheel drive aptera and remove the two font hub motors I would hope the car would still run on just the rear hub motor. I would lose power steering, most regenerative braking, traction control and a few other drawbacks but gain efficiency.

              After thinking about it it’s probably not worth it but my point still stands.

    • James Castaneda

      Member
      June 15, 2022 at 1:33 pm

      Qiang, I was thinking the same thing. Too bad the front motors could not be disengaged in an “eco” mode or something. That would be awesome! That would definitely make AWD worth it in my opinion, offering the best of efficiency most of the time, performance when you want it, and traction when you need it. Maybe in time they’ll figure out a way to make this happen.
      Chris Anthony and Steve Fambro… you guys listening? Ha!
      That and a McLaren F1-style three-seater configuration and I’d be in heaven! I mean, delete the transmission and e-brake tunnels, of course to open it up, but you get what I mean.

Viewing 1 - 7 of 7 replies

or to reply.

Original Post
0 of 0 posts June 2018
Now