Aptera Reboot - Improved

[Isaac Zachary]

Originally Posted by Snax

At this point, I am just taking a position to believe it when I see it.

I think this is a marketing failure given their intent to produce something unique at what is a premium price point for most people in a vehicle with marginal utility. They are banking on optimism.

You have to take risks to make change. The VW XL1 seems to have been a success.

Personally I'm fed up with the whole false advertising that internal combustion vehicles have come a long way. Sure, they get a bit better fuel mileage, better emissions and are safer. But they're still the same box on wheels with combustion powered pistons as they were over 100 years ago. Where are the flying cars, the maglev cars, the cars that have a Mr. Fusion, the cars that truely run on water, wind, air, sun, etc.

The hybrid is a welcome change from the norm. And so is the modern EV. But it's as if EV's are based off of the same box on wheels ICE cousins. Just put an electric motor in there and a big cellphone batter and then focus everyone's attention on the large touch screen.

100mpg cars are possible. So are 200mpg cars. So are 300mpg cars.

But everyone's focus seems to be on going backwards. The biggest energy waster, other than ICE efficiency, is the un-aerodynamic shape of our vehicles. But in spite of that, everyone wants to drive an SUV... So now we need ginormous batteries for each vehicle because everyone will be wanting to drive electric Hummers in the future, as if that's the solution to the energy crisis.

If the Aptera can go at least twice as far as a Tesla Model 3 per kWh, I'd say it's a victory in the right direction.

I'd like to see car manufacturers make lighter, ultra-aerodynamic and ultra-efficient family vehicles and figure out how to do that without sacrificing safety.

[oil pan 4]

My leaf can barely get over 100mpg. So 300mpg is going to be a bike.

[Isaac Zachary]

Originally Posted by oil pan 4

My leaf can barely get over 100mpg. So 300mpg is going to be a bike.

The Leaf is terribly un-ultra-aerodynamic and super heavy.

A 300mpg family vehicle is possible. The Leaf is not a 300mpg family vehicle.

If you could cut it's weight by 2/3 and it's aerodynamic drag by 2/3 then it would be close to being a 300mpg vehicle.

Or we could just keep making vehicles taller, boxier and heavier...

[Flakbadger]

Originally Posted by Isaac Zachary

The Leaf is terribly un-ultra-aerodynamic and super heavy.

Can confirm, own leaf. Is a box. Actually pretty stunning how bad it is from an aero standpoint, for it being an electric car and all. In city driving, it's easy to blow the EPA estimates out of the water--but get on the highway and suddenly you're struggling to break 4.2 mi/kWh, even driving reasonable speeds and drafting (SAFELY, 4 second gap, right lane only) semi trucks.

Hell, even UNsafely drafting at ~2 seconds is still not improving that number much. Hey, guy's gotta test here and there.

Since the world ended about a year ago, I've been pretty much just driving highway miles to a town that doesn't suck for curbside pickup of library books and groceries, and every so often to the fish store ~40 miles away and back (also curbside pickup. Pretty swanky). Generally average a solid 4.0-4.2 mi/kWh. I feel that if you could put the same electric guts in my old Yaris I'd probably get closer to 5 just from the better aero profile alone.

[IamIan]

Originally Posted by Flakbadger

Generally average a solid 4.0-4.2 mi/kWh. I feel that if you could put the same electric guts in my old Yaris I'd probably get closer to 5 just from the better aero profile alone.

Using EPAs ~33kwh per equivalent gallon

At 4 m / kwh .. you're getting ~132 MPGe in your Leaf
At 5 m / kwh .. you would be getting ~150 MPGe

[IamIan]

Originally Posted by oil pan 4

My leaf can barely get over 100mpg. So 300mpg is going to be a bike.

Your signature claims your Leaf gets you ~141.6 MPGe 90 day average.

[oil pan 4]

If I drove it like a normal person it would get more like 100.
Also batteries are heavy. The leaf could lose 600lb of battery but then it would only have like 4 miles of range.

[Isaac Zachary]

Here's the way I look at it. The progress of every technology has a limit. When you reach the limit you have to change technologies or explore other options.

Efficiency
For an example one of the biggest contributors to better fuel mileage has been increases in engine efficiency. Back when steam cars were replaced by gasoline cars the efficiency doubled from 5% efficiency to 10%. With time that doubled again to 20% efficiency. Now we have cars that get double that at 40% efficiency. But how many more times can we double engine efficiency. Only one more time, which may not be possible with ICE's but is possible to get with EV's. But after we make EV's (or ICE's or whatever else) 99.9% efficient there isn't going to be any major gains to be had in the efficiency department. And even to get to that point of near 100% efficiency the costs may make it too impractical for mass production.

What next?
So how else can we improve mileage? Two major things come to mind, aerodynamics and rolling resistance.

The future of aerodynamics
Now aerodynamics have come a long way too from the early days of the horseless carriage. But there's still a long way we can go. And unlike the cost of desgning a 99% efficient charger, battery, motor controller and motor, the cost of a more aerodynamic shape is not necessarily going to cost that much more.

There are three ways in which we can lower the aerodynamic drag. One way is to just drive slower. I'm not sure everyone would be on board with this one though.

The second is to make cars have a smaller frontal (or cross-section) area: shorter, skinnier, and (if you really need the room) longer. Of course we can only make cars so short and skinny before they become impractical.

The third way is the shape. How close can we get to an ultra-aerodynamic tear drop shape? We already know the limit, it's about 0.045 coefficient of drag, about 1/5 of that of most modern cars.

In other words if we want to cut the aerodynamic drag by 80% we could either cut speed limits by about 60%, shrink down modern car shapes by 65% shorter and 65% skinnier, or just make the shape nearly a perfect 0.045 Cd, or do a little of each.

Rolling resistance
The next biggest energy sponge to deal with is rolling resistance. Of course we also have limits here as well. But lots of older cars weighed a lot less than modern cars and with older materials, so ligher cars should be possible. If we could make cars weigh half of what they do then rolling resistance would be not quite half of what it is (assuming that the people and cargo don't lose weight too.)

Of course the BEV presents a problem with it's ginormous battery. Maybe we should be settling for smaller range EV's anyway though. The Nissan Leaf battery could be nearly 1/3 it's current weight with the right batteries. But the current trend to people wanting a 500-mile range battery is a problem for reducing rolling resistance. Unless we could do something other than rubber tires. Maglev? Metal rails?

The point
The point is that if we continue to do what's being done now, there won't be any major increases in overall energy consumption. We won't be able to significantly increase engine/motor efficiency like has been done in the past since there's no way of doubling the efficiency of an ~90% efficient EV motor. The current box vehicle shape will never be much below the ~0.250 Cd that it stands at currently, and not anywhere near the 0.045 it could be. And if something isn't done to figure out how to significantly reduce vehicle weight, a lot of energy will continue to be waisted in heating up rubber and pavement.

And all this means that humanity will either have to give up on the idea of motorized transportation or continue to burn up massive amounts of fuel, use up massive amounts of battery materials, and keep using up other valuable resources unless people start going in the direction Aptera is headed. Make and use vehicles that use significantly less energy than they currently do.

[freebeard]

The current box vehicle shape will never be much below the ~0.250 Cd that it stands at currently, and not anywhere near the 0.045 it could be.

Never happen. As soon as you add wheels you're up to 0.10 minimum.

The obvious path forward is an as yet un-mainstreamed mag-lev ground effect.

[Isaac Zachary]

Originally Posted by freebeard

Never happen. As soon as you add wheels you're up to 0.10 minimum.

The obvious path forward is an as yet un-mainstreamed mag-lev ground effect.

There are a few hat have been built are under 0.10, like many of the Ecorunner vehicles, some of which sit at about 0.05 Cd

But 0.10 is still half to a third that of your average car.



I'd love one of these with Maglev please.