from my experience
i used to drive mazda 929 wif 2.0v6 engine
auto
it cruise at 110km/h wif 2k rpm if not mistaken
as now driving S/neo
also auto but 1.6
in the speed of 110km/h
i think the rpm is above 3k since 80km/h adi need 2.5k rpm adi -.-
should b looking for the power of the engine instead of juz rpm i guess
RPM reading @ 110km/h, survey