Vitz 2001 1.0 manual rpm

[diesel2901]

Hello friends

First of all, thanks for making this forum a platform for discussing about our cars. I would like to apologize if I am posting at the wrong place; this is my first post.

I own a 2001 toyota vitz imported from japan (1.0, 1sz-fe), with a 5 speed manual transmission. I recently installed a tachometer (thanks for all the help about that). However, I am having some "headaches" as I cannot really decipher the rpms.

First, the car idles at around 400 rpm after being warm (starts at 600, drops to 400). Also, I do not really know when to change gears. Normally, for example, I shift from 3rd to 4th once the car reaches 40km/h; but then, the tach shows around 1400 rpm. I hit 2000 rpm in 5th gear at 80km/h.

Is this normal? I often read that gears should be changed at around 2000 rpm but it seems too much for the little engine; it starts screaming at 2000rpm and 3000 is a pain to the ears. I was wondering if the rpm readings are right, and if this behaviour is normal for the engine. it seems to be designed to operate optimally at low rpms (below 2000 at least, or is my tach giving wrong readings?)

Thank you for your advice!