Ok, they should come on about half way, maybe a little over. With the std switch, mine used to do what urs do. I changed it to a variable thermostat, so now i can set it to come in wherever i want. Mine will go upto just over half at the very very most - but drops quickly as soon as u start moving.

Dont forget - upto 3/4 in heavy traffic is no problem - won't do any damage.