Rhiannan Iffland stepped to the edge of a platform nearly seven stories above Boston Harbor, with thousands of cheering fans packed onto docks, roofs, and sidewalks below, and soared through the air ...

If you’ve ever rolled up to a red light, felt the engine shut off, and had that half-second of “Wait… did my car just stall?”—you’re not alone. Auto start-stop systems are now standard on a ton of ...