Today’s ICE is getting to be what, upwards of 40%? At best we’re only going to double what we can get from it, and I think those with thermodynamic backgrounds could explain where the actual limit is, with the Otto cycle.
A big lumbering big block, small turbo at low pressure (mostly to offset power loss at altitude)—I have to wonder if that couldn’t be a smooth low cost path for vehicles that spend most of their time under load. High pressure engines can better deal with low load situations, while doing ok under high load, but I wonder, for vehicles expected to last years and years, if a bigger engine at lower boost might not hold the edge. Just a swag.