anything under 40 i pkug mine in for easier start and faster heat. never used the cardboard trick. but my grandfather was a 60's-70's ford guys, and all his trucks both I6 and V8 gassers he would put a lower temp thermostat in them for the summer, then have to use cardboard on the radiator in the winter just to have heat. it was his way of doing things and by god it worked. if you didnt have cardboard in the winter those trucks would run so cool you couldnt even get warm air inside let alone hot air.

 

I don't bother to plug mine in until -20c (-5f) and then it's on a timer for 3hrs before take off time. If i am out were there is no plug in i just cycle the heaters 3 or 4 times and she goes like a charm. Good batteries and these things will start no problem at -35c no plug.

 

I plug mine in if it's below 60*. I hate winter time.

 

Below 60*! You would have to plug it in about 8 out of 12 months here. Do you mean at night or during the day, because that might change it to 5 months. Man, some people just can't handle the cold.

 

Aw shucks guys. I don't plug in the heater until I see a rabbit get a jump start off a beagle. . We are having a cool wave down here. Might even get into the thirties tonight.

 

60* at night is cold for me. I'm a whopping 145lbs. And if I'm cold, then my truck must be cold and I don't want it to catch a cold and get sick on me. Lord knows I can't afford the doctor bills on it right now.

 

Dodge says the block heater is not required until -40. And i might add that it actually IS possible to start the truck that cold if it is not plugged in , but it sure does fill the garage with smoke about 10 times over before it smooths out... hehe.

Honestly , our 97 might get plugged in a half dozen times each winter. When dad takes it to work ( potash mine) it sits in the middle of a huge parking lot, and it has never ever failed to start. we just cycle the grids twice , then hit the key. We have had to boost the odd powerstroke that wouldn't start that cold.

 

ive never used a block heater even in -10 degree weather, on any of my diesel trucks.

my 3rd gen starts on second or so crank in winter time.

my good ole ford dump truck with the old 6.9 ferd in it, starts on the 5th or 6th crank, without the block heater

 

.....and I thought I was craaaaaazzzzyyyy

I don't even have them grid heater things and mine starts at 0* with no problem
and it has never sucked on the ether jug.

 

I plug mine in if it is going to be below 40°. Not really needed, but my commute is only 8 miles so I like to get the engine at least warm. Plus, I don't pay electricity

 

Just a note of caution to you cardboard insterting diesel dudes, I read on here somewhere you need to put a 6" hole in the center of the cardboard to allow the fan & fan clutch to get some air. Also, with cardboard there is less air flowing threw the innercooler. The pros & cons of cardboard wind breaks are up for debate.

I only use my cardboard below 0.

 

Sure it will start down below zero without plugging in, whether it's good for the engine is another question.
I plug in below 40F, don't mind paying the 30¢ a night it costs to run the heater.
Many of the big rig owners I know plug in below 70F.

 

I'm wilth Bill--I plug in more for the sake of warm oil at startup than anything else.

 

I'm only 12 miles to work so I plug mine up to at least boil the water outta the oil. Got mine onna timer. I gotta try the Honda generator thing because I can't pluggin at work anymore.

 

Mine gets pluged in all day at work and on a timer for 3 hours at home in the garage. I pluged it in yesterday at work because it was 12* out and I only have a 8 mile drive. It was 35* or so in the garage so i dident bother at home. I typicaly try and plug it in anything after watter gets hard but anymore i dont do it as much as I used to.