Hmm... I'll play devils advocate here, probably because I haven't seen the existing data yet, but this makes sense to me. If we're only running on two cylinders, we only make half the power, and can run the motor much closer to WOT for the same fuel consumed and power outputted. This means reduced pumping losses.
Why won't this work?
If this setup alternated between cylinders 1,3 and 2,4 ever few seconds, it could probably lower overall engine temps and reduce cooling needs. I remember reading about how the Cadillac Northstar cars could run w/o any coolant by cycling off 1/2 of the cylinders at a time and using a bit of fuel to cool the ones that weren't firing; sort of a keep-alive mode until the car made it to the next shop.