Low rpm does not mean fuel efficient, there are too many variables and looking at rpm alone is absolutely worthless.

Certain engines are build to burn more fuel for absolute power(torque) into the driveshaft, it is "heavier & harder" to make a turn hence the low rpm but high speed.

High rpm - technically are more fuel efficient if the engine mechanism are designed to run on a low torque high rpm - ie: same speed as above however lesser fuel is required since it does not need to put out such a high torque into the drivetrain. 

Anyway rpm is not one of the way to determine fuel efficiency, infact low rpm is not efficient for practically everything within the concept of mechanicals

2,000 rpm - 110km/h

1.7l engine.

What car ?

I've driven a few cars mainly from Proton. I suspect the speedometer itself isn't entirely accurate after comparing to Garmin GPS (perhaps other phone GPS navigation speed meter can cross check also) speed meter doesn't tally during the journey. I recall seeing Proton speedo under register the actual speed to GPS, about 5km/h off, but Perodua Myvi meter is nearly spot on. I assume Toyota would be spot on too. My findings is from using the same Garmin GPS in all these cars going outstation journey.
So begs the question, are all those 110km/hr readings really spot on? Which can be erratic? The car speedo or the GPS?

Harrier 3.5G

110km/h - 1.2k rpm

which car is  1.5l and below but lower than 2500rpm at 110kmh other than city? this should be very fuel saving on long journey. how about mazda 2? anyone knows?

         

you jgn jelly his crusing RPM = your idling RPM

Harrier 3.5G

110km/h - 1.2k rpm

Omg bro !  Any typo there ?