how cold before plugging in block heater
Logistics Pro
Joined: Mar 2007
Posts: 4,604
Likes: 4
From: Claremore, OK
I'm going to assume the 7.3L uses the same style/wattage heater as the 6.0L since Navistar built both. Which would be a 1500 watt heater. Maybe they do use an extra $15 a month, but how much diesel would you burn waiting for the engine to warm up? I'm willing to beat more than $15 a month.
Posting Guru
Joined: Jan 2008
Posts: 2,408
Likes: 0
From: Trenton, MI
I'm going to assume the 7.3L uses the same style/wattage heater as the 6.0L since Navistar built both. Which would be a 1500 watt heater. Maybe they do use an extra $15 a month, but how much diesel would you burn waiting for the engine to warm up? I'm willing to beat more than $15 a month.
It first time I had powerstroke in winter. Last year I had idi 6.9L that wasn't FUN to start. Plug block heater for 2 hours then Pray it would start. There couple times it won't start. I end go crazy and use plumber torch heat on bottom of exhaust manifold. Leave heat for about 5 mins. Then jump in truck and crank it start.
My plan this winter I wouldn't plug if it really cold then plug for 1 hour then start. Idle 2-3 mins then drive slow until engine temp go up.
< Samantha...my Co-Pilot
Joined: Dec 2001
Posts: 768
Likes: 11
From: Fallon, Nevada
It would be like burning 10 or 12 100 watt lightbulbs for whatever time you have the block heater energized (somewhere around 1000 or 1200 watts...don't remember the specification)...buy a heavy duty timer for around $10 or so and set it to turn on for two to three hours before your anticipated start time. If you had a set of guages you could monitor your coolant temps and adjust the timer duration for more or less depending on your ambient temps in you area. Good luck.
< Samantha...my Co-Pilot
Joined: Dec 2001
Posts: 768
Likes: 11
From: Fallon, Nevada
Just a comment for this thread...5W-40 Synthetic will make a big improvement in cranking and starting compared to 15W-40...provided all things are in proper working order. Even 10W-30 will make some improvement...but I know from experience that 5W-40 is a huge difference when temps are in the single digits.
More Turbo
Joined: Aug 2006
Posts: 548
Likes: 7
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< Samantha...my Co-Pilot
Joined: Dec 2001
Posts: 768
Likes: 11
From: Fallon, Nevada
5W-40 Rotella T6 and it is 11 degrees here this morning. The heater is plugged in...truck spins up quickly and no strain on the battery or starter or anything else...except maybe the wallet 'cause of the power bill. The truck will warm up quickly and the frost on the windshield will not last. Someday I may look at the power bill and get the cost per Kwh and know for sure what it cost...don't really care...just curious.
Senior User
Joined: Nov 2010
Posts: 419
Likes: 1
From: Iowa
I figured it up last year. It came out something like it was twice as expensive to not plug it in by the time I would start it and high idle it for 5ish minutes vs plug it in for 2hrs and take off slow. I might have lower electricity rates than some of you though.
Junior User
Joined: Jul 2007
Posts: 84
Likes: 0
From: Nebraska
I rarely plug my truck in and I'm from Norther Nebraska. I will plug in if lows are below 0 but thats about it and mainly so the cab warms up faster. I have on several occasions sarted my truck, after sitting out all night, at -15 and lower. That happens when I am in Colorado on snowmobile trips and have no place to plug in. I also did the same with my 7.3 but my 6.0 does a better job of starting. Its amazing how well our 6.0's start when cold.
CFS
CFS
Junior User
Joined: Apr 2010
Posts: 86
Likes: 0
From: Eagle, ID
If you want to go by the "6.0 Liter Power Stroke Direct Injection Turbo Diesel Owner’s Guide Supplement" owners manual, this is what it says:
Cold weather starting
1 - The engine block heater must be used for starting when the temperature is -20°F (-29°C) or colder. Refer to
Using the engine block heater (if equipped) in the Driving chapter of the Owner’s Guide.
2 - When operating in cold weather, use a minimum of 45 Cetane Diesel fuel or use Cetane Index improvers from a reputable manufacturer.
But of coarse others have their own thoughts on when to use it, just throwing out what the manual says for reference.
