[bhtooefr]

…so I decided to do a quick and dirty photo edit of a pic on the site, to show what an Aptera narrowed to 2 m wide solely through bringing the wheel pods in would look like.

It’s an ugly one, as I didn’t address the background properly.

At that narrow, you actually would need to fair the front wheels into the body instead (and then you’d want to consider going even narrower to minimize frontal area, at which point stability starts becoming more of a concern, as well as footwell packaging).

Also, it looks like, based on counting pixels (582 pixels between the outer edges of the wheel pods, 454 pixels between the outer edges of the body shell), the body shell is about 68.6″/1.74 m wide.

[bhtooefr]

A few days ago I posted a few thoughts on modifications to the design so that Aptera could fit into the L5e-A vehicle class over on Reddit, and thought I’d bring those comments here, with a few edits.

Realistically, I don’t think the first model will actually be sellable in any region following UNECE vehicle regulations – you can’t make a three-wheel category M1 or N1 vehicle, they’re forced into category L5, and category L vehicles are maximum 2 m wide, 4 m long, both of which they exceed.

The length (currently 4.37 m)… shortening that simply will increase Cd and decrease solar panel area, no way around it.

The width (currently 2.24 m)… apparently they don’t actually need such a wide track for stability (source from the FAQ spreadsheet), they need it for aerodynamic reasons, to keep the wheel pods away from the body shell to minimize Cd.

The ways to deal with that:

• Narrow the tires and then the wheel pods, which would reduce width and frontal area, at the expense of front traction, although Cd should be relatively neutral. Realistically, I’m thinking about 145 mm wide tires are about the narrowest they could practically go, from the currently specified 195 mm wide. (125 mm wide LRR tires exist, but only on 13″ wheels – AFAIK the Elaphe motors that Aptera’s using require a minimum of 15″ rim size – and only designed for a vehicle half the weight with an 80 km/h limiter.) That only gets you at most 100 mm of width back (this assuming you keep the inside edge of the tires’ location fixed, and therefore reduce the track width by 50 mm), though, and you need to get 235.2 to fit in the 2 m maximum.
• Narrow the body shell, which would reduce interior space, safety, and potentially solar panel area, but would reduce frontal area. Shouldn’t affect Cd significantly. Worth noting that Aptera ‘s moving the seats inboard by 25 mm (each I think – source from Transport Evolved), so that means there’s 50 mm of free real estate if Noir’s side impact space was acceptable. Now we’re to 150 mm of the 235.2 mm needed (and may be able to take more of that).
• Bring the wheel pods closer in to the body. This increases Cd due to accelerating the air between the wheel pods and the body shell, although it might slightly reduce frontal area due to reducing suspension arm length. It also reduces stability, but that should remain within acceptable parameters, and widens the turning circle. (There may be a point where it makes sense to take a frontal area hit and fair the wheels and suspension into the bodyshell as well to keep Cd down, instead of having separate pods.)

There’s also a couple things I don’t like about the 145 mm LRR tire selection – 145/65R15’s two applications are the front tires on the 450 Smart ForTwo and the Mitsubishi i-MiEV, both of which are RWD, so none of the 145/65R15 tires on the market are designed to be drive tires. If going for i-MiEV tires, though, it may also be reasonable to downsize the rear tire from 195/45R16 (or the potential for something 205 wide) to 175/60R15, which is the rear size for the i-MiEV, and therefore is available from the same vendors. That’d save a touch of frontal area to offset additional drag elsewhere.

A couple other thoughts I didn’t put into my Reddit comment: with 9″ of ground clearance for the belly, there may be potential to drop the bodyshell 2-3″, which would reduce frontal area for the rear wheel further, as well as restore at least some lost stability from narrowing things.

Worth noting that every modification other than narrower tires and wheel pods may well require a different bodyshell – hence my stating that I don’t expect the first Aptera to be available in UNECE regions. (And, the current FAQ does hint at this outcome.)

I’m not sure if the Elaphe motors are narrow enough to support a narrower tire – if not, then that option wouldn’t be practical without a motor redesign (and subsequent reduction in performance, although the European market may well accept that reduction in performance – a 0-100 km/h time of 8 seconds is decently quick there as I understand, where a 0-60 MPH time of 8 seconds is slow here).

[bhtooefr]

My take is that there’s plenty of room for both in the market.

Lightyear One has a more conventional layout and shape, five seats instead of two, about as much cargo space with the rear seat up and ~2.4x the cargo space with the rear seat down, and is narrower (extremely important for some markets, unimportant for others).

Aptera has higher efficiency and therefore longer range on the same battery or the same range on a smaller battery, a larger battery option (Lightyear One is 60 kWh only, Aptera has a 100 kWh option), lower cost, but with the downside of only 2 seats, more controversial styling, and the “if you don’t hit it with the outer wheel, you hit it with the inner wheel” problem with hitting bumps inherent to a three-wheeler.

[bhtooefr]

Looks like estimates are 1300 kg – compare to Aptera’s target of 816 kg for the same size 60 kWh pack. However, weight is less important with an EV’s efficiency, as you get some of that energy back under regenerative braking.

Aerodynamics are what’s far more important, and there, drag coefficient is higher – “under 0.20” versus 0.13 for Aptera. (I’m not about to compare frontal area – I suspect it’s not actually that different, due to Aptera’s being much wider and taller, but the wheels being podded and away from the body.)

Lightyear One’s charging speed versus efficiency estimates imply about 1000 W of panel, versus 700 W for Aptera. (There may actually be more – I’ve seen some estimates that imply over 1200 W of cells based on their 5 m^2 of area, so it’s quite possible that the curvature of the panels limits insolation and means that you’ll never actually hit a 1200 W peak, and 1000 W is a realistic limit. If that’s the case, Aptera may also be somewhat lower realistic peak.)

One big thing that accounts for differences in claims, though: Lightyear One is using the WLTP cycle for their claims – the standard in Europe – which typically is easier than the EPA test cycles that I believe Aptera’s claims are based on (I think there are a couple exceptions, where Tesla actually has shorter range on some models WLTP than EPA, but the vast majority of cars have shorter range on EPA than WLTP). It’s fair – and in fact necessary – to use WLTP for a product meant for the European market, but it means their range claims aren’t directly comparable (and WLTP ranges tend to be optimistic).