I see you have a Cummins. Get the block heater plug if you don't already have it. Get a timer for your elec cord and plug the block heater in at night. I'm assuming this is for going to work. You'll have warm air way faster.
If you're randomly using your truck and a timer wouldn't work, then start it up and use the cruise control + set and it will rev the CTD up and it will warm up faster.
On a 30-35* night with my block heater on for 3-4 hours in the morning, my truck's temp will reach 170+/- a couple degree's in a little over a mile driving 30-35 mph. I go to the gym in the mornings and it's a short trip so having the truck warm up faster helps the truck and me.
FYI I have a 2012 CTD.