Aptera Range at Speed Spreadsheet

Thanks for the spreadsheet! While I understand the accuracy probably isn't exact, perhaps not even overly close, it actually answered a lot of questions for me.

Here is what I was wondering and what it sort of answered for me.

If I took my 1000 mile Aptera on a 1000 mile drive at 80 MPH, how many stops would I have to make? Let me re-ask this a few times so you see the real world experience I'm coming from...

If I took my 260 mile Bolt on a 1000 mile drive at 80 MPH, how many stops would I have to make? Answer: I wouldn't do it. The charge time is to long. Great car if you stay near its full range for the day, not a long haul car though.

In my Tesla LR Model Y at 310 mile range? It would take about 7-8 stops. I would do it but my wife won't let me, it adds to much time for her.

So back to my Aptera, based on your chart, I would get 647 miles range at 80MPH. At 80% of that number, I'm just over 500 miles and if you've driven electric cars, you know you need some 'buffer' to deal with some unknowns. So, 80% seems safe to me. During my 1000 miles, I might get by with 1 stop but realistically, I would do 2, which would approximate the number of times I'd have to stop for gas in an ICE vehicle anyway.

Of course, if I slowed down to 70, which is the speed limit in most of the US, I could do the trip with 1 stop with lots of room left over.

Now, my bladder thinks I'm okay with the 7-8 Tesla stops, but I prefer the flexibility of fewer stops.

all conjecture at this point until final production vehicles are tested and evaluated both by Aptera for marketing spec sheets. Of course after EPA testing we will hae the gov's view of performance. Some amount of engineering changes are taking place before production vehicles that will affect these numbers.

Also using deterministic calculations vs. stochastic in the calculations will result i n inaccurate final values. That is why Aptera uses simulation rather than deterministic approaches in their engineering design

Thanks Charles, I strongly agree that Aptera will almost certainly do dramatically better than any current car, as shown on the spreadsheet, however:

- I can't view the Zoe story very well, but it appears to be at constant speed, so the real-world numbers with acceleration & regen losses should be much lower, like the spreadsheet.

- Line 20 of Aptera's FAQ spreadsheet says "We use 100Wh/Mile at the EPA driving cycle with a max speed of 67 mph."

- My sheet shows Aptera beating its specs at 20mph, so I don't see how you figure it won't make its specs at 19mph. Either way though...:

I've recently learned that:

- WLTP uses a smaller % of highway miles for their overall specs. So even if they use a higher highway speed than EPA, the average speed may still be lower.

- EPA runs a car through a specific acceleration/cruise/brake(/stop?) cycle on a dyno until it dies, & just multiplies by 0.7! NO consideration of weight or drag. This explains why big heavy Teslas do worse than their specs & my small light Fiat does better. Aptera should beat EPA specs by an even greater margin, being much smaller & lighter than even my Fiat.

- Aptera announced 10% better range with FWD. The spreadsheet is based on AWD.

- Aptera announced a number for range vs weight in a recent vid, so if someone finds that & posts the link/time I could factor it into the lighter weight models.

Oh sorry they aren't the same weight as the Zoe was listed in Kg. 1976 kg = 4356 lbs. vs Aptera of about 2500 lbs (with full payload). Aptera should be dramatically better than the Zoe at same speed.

"Aptera's own published specs are supposedly based on an EPA test cycle which apparently has an average speed of 48mph & peaks at 67mph." I have not seen a confirmation of this statement. After looking at the specs for the EPA test and the WLTP test, I seem to lean toward the WLTP being the more likely basis. (which favors a higher speed closer to Highway speeds in the US)

The spreadsheet itself seems to disagree considerably with the Recent Record Distance set with a Renault Zoe of 475 miles at 19 miles per hour. https://fleetworld.co.uk/renault-zoe-reaches-475-miles-on-a-single-charge/

(the spreadsheet above seems to imply that Aptera wouldn't even reach its stated 250/400/600/1000 mile range at that speed - and certainly not set a record that was over 124 miles more than the previous record. ) Granted we don't know how the tires would compare between the two but the Aptera is almost the same weight as the Renault Zoe but certainly is more aerodynamic.

Thanks for the update. Even better!

Thanks for reminding me the lower-range versions will actually be better, & THAT is also not factored into the spreadsheet!

Lower range &/or FWD models with better efficiency will also gain more miles from the same solar panel option, AND even parked inside every day it will take less time/cost to charge.

Even better if they offer RWD & 10kWh battery.

I'm new to the whole EV scene, but if Aptera can achieve 1000 miles with all-wheel drive, by using front-wheel drive wouldn't the 1000 mile variant actually achieve more distance due to using one less motor?

OH! Motor efficiency likely also varies with speed, but unfortunately I have no idea how much.

New version is more believable, but it still ignores the energy used for acceleration (not all of which is recovered by regen). If you get on the freeway and set the cruise control to 70 mph, and just stay there for hours, you should get a better range than this indicates.

Wow, .002 ! !

Note that in the recent meeting with the Denver Electric Vehicle Council that I am pretty sure Nathan Armstrong indicated that the latest Drag Coefficient was actually 0.128 not 0.13.

CHART UPDATED!!!

HUGE thanks to Biff for pointing out that rolling resistance is constant per mile, so that's now factored into the link & pic in the top post above.

Also thanks to Ken Kobayashi for confirming Biff's point.

@Ken Kobayashi Right, it's impossible to get it exactly right, but I think we're getting pretty close now, & there are always going to be unknown variables like weather change during your trip. Acceleration is a factor of course, & was included in the EPA spec that the rest of the chart is based on. With Aptera's direct drive hub motors, regen deceleration will negate even more of the acceleration drain than other EVs already do, making it a smaller factor.

This spreadsheet seems to assume there are only 2 components of power usage on the car: air drag, which is proportional to 3rd power of speed, and a power drain that is constant regardless of speed. So it is ignoring 2 other factors: rolling resistance, which is proportional to speed, and acceleration, which is proportional to the derivative of speed.

This is why it is showing a very high component that is independent of speed (3.1 kW). In think in reality, power consumption is much less than that at 0 mph, and there is a fair amount that is proportional to speed. I know it's impossible to calculate each component based on the one published number. But I think if you at least make an educated guess, rather than assuming those components to be zero, you'll find that the efficiency peaks at a lower speed.

@fanfare Please stay tuned for a more accurate update.

Been looking for a chart like this for the longest time. Thank you!

You need to consider the rolling resistance separate from the base load, since the rolling resistance is calculated per mile (energy/mile) and the base load is per time (energy/sec). The rolling resistance is usually much larger than the base load unless HVAC is cranked, so the non-aero kW used row in the spreadsheet is not independent of speed.

I would be very interested to see if you can produce the "EPA" results for existing cars with this spreadsheet (like the Tesla Model 3 or Tesla Model Y). Most of the range tests I have seen (especially at Highway speeds like 70mph) are quite a bit below what is quoted in for EPA Highway Range Rating. (typically 8-10% below at least) Here is an example: https://www.youtube.com/watch?v=8SakFvVYWAk

Efficiency – a calculation

http://aptera.nu/?p=67

@ralenz2009 Ya, that's why I wrote "same battery temp, same amount of acceleration/braking, etc.".

It seems to me that cold weather's biggest factor is the one I haven't yet seen specs for: Battery capacity reduction:

- Users report only 1kW of resistance heat is needed to keep a 500e cabin warm when it's below freezing out.

- Air density itself drops range less than 8% when temp drops from 90F to freezing.

- But those two add up to much less range loss than users are reporting, so the battery must be a big part of it. When I put my phone in the freezer for a few minutes to simulate parking outside at Xmas in NY, my free AccuBattery app showed voltage dropping a LOT.

I'm ordering a 600kw model and was hoping to get 500 miles range. Looks like I'm right on.

Disclaimer: I just did the exact same spreadsheet for my own BEV, & it doesn't match my 5.5-year real-world experience. The very best range I ever get is in "nice horrible" 10-15mph L.A. freeway traffic, but the sheets show the best range just like Aptera, around 48mph.

Still, publishing it may prompt Aptera to "man-up" & publish the high-speed range specs that no other (250% less efficient) EV would DARE to publish.

Unlike gas cars like the Insight, most BEVs' peak range is at an impractically-low speed like 15mph. However Aptera's extremely low air drag means that the other factors are a much bigger % of total power.

That's why the spreadsheet shows peak range at around 45-48mph.

The steady 3kW non-aero loads burn the same power per hour, so at lower speed they burn more energy per mile.

Thanks for sharing. Looks good to me. I drive a 2000 Honda Insight and know all about efficient driving and lower speeds to the maximum performance. I can get 100 mpg with tires at 50 psi, a 10 mph tailwind, good premium gas and driving on cruise control at 50 mph. I did that performance for 100 miles without my foot on the pedal.