Lugging an engine, (higher gears at lower speeds) not good. Tough on the rod bearings.
I use the tack and pay less attention to what gear i'm in. keeping it around 3K. not below 2K and shift at 4 ish.
unless I'm in play mood, (which is often) and winding it up a bit. down shifting and using the motor is loads of fun too.
If you're gonna drive around at 2K rpm all day, then you should have a Prius
These cars were meant to have fun, use it!