It is 9 F night now in northern Delaware. I had heat a few miles after I left work 20 minutes ago. It seems to heat up much quicker if you leave the heat on recirculate to pull air in from the cab as it heats up.

 

In our cold temperatures, if I leave the heat on recirculate and operate the fan, the interior of the windiws will be frosted oevr in a short time. I think I'll go the route of a removeable "block" for the radiator and just drop it in on really cod days where I have alot of shorter trips to make. Last night at -11C the warmup time was a few miles. When it is -34C, it can take forever!