On my recent trip to Far North Queensland in Australia, I encounted this sign. My RAV4 ascended the hill with only minor drama. In my Aptera I will not be able to comply with the sign, neither engaging 4WD or Low Range, which is also the case on my RAV4. In FAQ spreadsheet I found an answer where Aptera can climb a 6% grade for 10 minutes no problem. Can it climb a 27% incline?
Tires make a HUGE difference, to nearly everything, such as miles/kWh, acceleration, braking, cornering, on dry pavement, wet pavement, dirt, mud, snow, ice, etc, etc, etc...
Keep in mind that Aptera is only around 2,000 pounds, with about 700Lb on each wheel, & seems to have a relatively low center of gravity for low longitudinal weight transfer on acceleration/braking/hills & laterally on corners. I'd put my money on that, over a heavier, higher vehicle like a RAV4.
Now that you've relayed more details, I think I'd be more concerned about Aptera's excessive width if another car came the other way, especially if it couldn't stop, like you couldn't.
I'm looking forward to more replies about this tomorrow.