Being my first diesel and since it won't fit into the garage, it's too long, I was wondering what temp I should start plugging it in at, how long before I start driving after start up and anything else good to know about a 7.3 in the cold.
BTW it's wintering on Cape Cod just a mile from Hyannis Harbor...Very COLD!
Back to NC by February.

 

iv never plugged mine in before.they just start like always.they don't warm up quickly just sitting.so i just head right out.

 

I used to have an '02 PowerStroke (so different from yours, but probably still some similarities). It usually started OK down to about 10 deg. From there down to about -15 it almost always started, but sometimes it took quite a bit of cranking. So I bought a timer that would turn the block heater on about an hour before I left for work. I'd use it if the temp was going to be below +10 deg.

 

It will very easily drop to 10 and below in MA on the ocean. We've had some cold mornings here in the Smokeys, I've already noticed it does not warm up fast. My truck has a programmer in it. One of the cool things about it is that I can hit the digital display to #1 and it will fast idle @ 1100 rps.
I'm sure I'll figure it all out.

 

+1 timer; the block heater draws 1000W, so whatever your per-kWh rate is on your utility bill, you're paying that much for each hour you run it. An hour won't do much, but you don't need it plugged in all night. Set the timer for 2-3 hours before you expect to start it.

I would start using it at 20F or below. It's not just _whether_ it'll start, but at what "cost". Cold starting puts the most wear and tear on any engine. A few degrees of oil / coolant temp makes a big difference wrt. the friction involved in a cold start.

My general winter-readiness regimen:
* Lund Cold Front in the grille
* Winter blend fuel, Power Service white bottle in each tank
* Stancor GP relay
* Strong batteries
* Block heater when possible
* Extra GP run time (20-ish seconds) when block heater not available

 

A halfway healthy 7.3 will start unassisted down to at least -40, I haven't had the misfortune of having to try colder not plugged in.
My winter prep consists of 0w40, checking the glows, testing the batteries, putting in the winterfront and changing tires.
I do not run any sort of fuel additives, but we have very good fuel here(we are normally on Arctic Diesel P50 by mid November) I have only gelled up once in 10 years.
I would not recommend doing this just anywhere though. I do carry a jug of diesel 911 just in case.
I do not buy into any sort of extended glow time or double cycling. Neither my 00 or my 96 250 ever failed to start turning the key after the wts light went out. When it is very cold, battery power spent on extended glow time is power you don't have for cranking.
My 96 250 ran its last winter on 7 glows due to melted wiring and didn't get plugged in at work, even during the weeks we had with daytime highs of -35. Started every time.

 

I'm probably going to buy an inline heater that actually circulates coolant. They use less power and give more effective heating.

Yes maybe you don't need a heater but it sure is a lot easier on things than working the gps, starter, and batteries every start.

 

The factory block heater circuletes by way of convection.