They give a well reasoned and sound explanation of where this figure comes from on their website. Go to the Performance tab under the Vehicle details section an check it out. Excerpt below....(this if for the Hybrid, not the all electric version)
With the Plug-in Electric Hybrid version of the Aptera(typ-1h) the mileage of the vehicle is difficult to describe with one number. For example, the Typ-1h can drive 40 to 60 miles on electric power alone. Perhaps for such a trip, the engine may only be duty-cycled for a few seconds or minutes. This would produce a fantastic number, an incredible number that, though factually true, would have no useful context, i.e. it's just a point on a graph.
An asymptotic decaying exponential is an accurate way to describe the fuel mileage of the Typ-1h. For example driving say, 50 miles, one might calculate a MPG number that's 2 or 3 times higher, say, 1000 MPG. As battery energy is depleted, the frequency of the engine duty cycle is increased. More fuel is used. at 75 miles, the MPG might be closer to 400 MPG. Again, we're using battery energy mostly, but turning the engine on more and more. Just over 100 miles we're just over 300 MPG, and just beyond 120 miles, we're around 300 MPG.
They go to say that if your driving on the engine for long distances, mileage falls to around 130 mpg.... still pretty damn good as far as I'm concerned.
The engineering thought that went into this little bug can only be called exquisite....I want one; not to save the world but because it looks like a hoot to drive!
the mileage of the vehicle is difficult to describe with one number.
True. So why not give us two numbers: MPG and miles/kWatt. It's not difficult:
Drive the car on battery power only until it stops. Fill the gas tank. This is the starting point. Do not plug the vehicle in and run several tanks from full to near empty over a typical driving profile. After enough miles to get a good statistical average, shutoff the fuel and drive the car on the built up battery charge until it stops. Fill the tank. This is the end of the test. Divide the total miles by the total gallons of gas. This should give a close estimate of MPG.
Then do a similar test running on batteries only, keeping track of the kWatts. Then do a combined test to account for efficiencies of dual mode which will bump both numbers up a little I would guess.
The quoting of other numbers is misleading. They do it to grab headlines. Consumers should demand they be explicit about MPG and Miles/kWatt, capacities of each, and total range. It's the only way to do an objective comparison.
But I guess marketing hype isn't about objectivity.