The situation today is different. This engine is supposed to optimize hybrid cars (it is supposed to generate electricity to drive an electric motor) and hybrids are something new, they haven't existed for more than a century, which means that there is likely more untapped potential for optimization. This engine wouldn't be practical in a standard gasoline car and it's not designed to be used in one.

It obviously can still fail but I don't think it's possible to draw historical parallels.