[ellenor2000]

Wouldn't running variable 20something:1 (basically, maximum lean running) to 11:1 (rich max) AFM with a high compression ratio, electronic spark control, diesel-type exhaust scrubbing and multiport direct injection on the late side of the compression stroke (similar to diesel) have reasonable efficiency? I mean, it's running lean, so it is burning more of the fuel and it's probably producing way too much NOx... but would it burn less fuel per horsepower at part-throttle, where the throttle would be more open for the same power level?

I realise Honda did a less extreme version of this, and probably Chrysler too.

But this seems pretty #Unicorn to me.