My car has just always done this. I dont know how it happens, it just does and I never wondered why until now.
When Im driving and Im approaching a light, cruising in 4th ill use the brake to slow down and then just put it in neutral and coast to the stop.
The engine will idle around 1000 rpm until just after I stop completely, then it goes back down to 650 or where ever its supposed to be.
Any reasoning for this