If that line
does show torque at WOT, that may make it incredibly useful: could you not essentially use it to extrapolate what throttle/pedal position to use to get the engine closest to the sweet spot at a given RPM?
EG. in the Saturn chart, 7/9 throttle @ 2000 RPM looks like it would put you squarely in the 250 g/kWh island.
Of course it doesn't work quite that simply, because the engine doesn't "idle" at 2000 RPM ("0/9ths"), so you'd likely have to factor in the amount of pedal required to get there with no load on the engine.
