My 2 sens:

Don't get too hung up with counting km/l with your RPM, it has less to do with your RPM than:

1. The throttle position. Obviously, going 2k RPM uphill consumes more fuel than going 2k RPM on a level road, because when going uphill you are pressing the gas pedal deeper, the throttle opens wider, more air goes in, more fuel is consumed.

2. How well you balance your speed with distance. Going 120 km/h on a 10km stretch of road consumes less fuel than going 10km/h for the same distance. This is where using the right RPM/speed for the right situation applies. You'd think that climbing a hill at 2k RPM may save fuel, when in fact revving higher and getting over the hill sooner may be more efficient.

So, it doesn't matter that the CVT cruises 110 km/h at 2.5k RPM and the Aichi Kikai MT box cruises at 3.6k RPM. As long as your throttle is opened the same amount, the FC will be similiar.

In my experience with my 1.6 CVT, the best cruising speed for FC is around 100-110km/h on a level road.
That's because at that RPM you are already running near peak torque, hence the awesome acceleration. The good thing about CVT is that it can rev freely without regard for speed, that means even when cruising at 2.5k RPM I can step a bit more to reach peak torque as if for that short moment the engine is disconnected from the drivetrain, more so if I harden my balls and reach for the L gear.

Make no mistake though, the CVT's efficiency is less obvious during highway cruising, in fact it is no different that regular AT or MT boxes. It only shines in driving conditions where you often need to vary the speed, eg. accelerating/decelerating in city roads, uphill climbs etc.

Again, just my 2 sens. Correct me if I am wrong.