Originally Posted by RSM
In Punto it remains same. I checked just now. It increases very little, hardly you can notice. May be from 900 to 905.
This, actually is a very good thing. The rise in rpms is because of the additional load on the engine. As the ac is switched on, load increases, and idle rpm decreases. To compensate this, ECU increases the idle. Most of the times it is over compensated, as in cooldhaya's verna. The negligible increase in your punto shows the attention to detail.