[serialk11r]

That looks good, but if you read the thing they say the trick is to get the mixture up to 1000K to get consistent burn, plus 50ppm NOx is too high (by a lot!). While getting the mixture up to 1000K is easier on 30:1 AFR, at idle that is going to be a huge challenge because you still have to run some manifold vacuum.

Though, with cooled EGR you could reduce the burn temperature a little more while still getting the mix up to 1000K if that is indeed a critical threshold for consistent combustion, but you'd lower the efficiency a bit with unburned fuel.

We should all hope that direct NOx catalysts become commercially feasible if we're going to hit those 2025 CAFE targets.