Plug in

[Anderc1]

My 2020 2500 High Country Duramax is stored in the garage.  I do Not plug it in since the temp is above 32 in the garage.  I am Going to NH and the truck will be outside, at below what temperature do I need to plug the truck in?

[Black02Silverado]

1 hour ago, Anderc1 said:

My 2020 2500 High Country Duramax is stored in the garage.  I do Not plug it in since the temp is above 32 in the garage.  I am Going to NH and the truck will be outside, at below what temperature do I need to plug the truck in?

I would think it would be fine until the temp gets below 10°F.    Using a high quality synthetic oil will help as well with starting in extreme cold temperatures.

[MTU Alum]

They will start at -30 f without being plugged in.  I probably wouldn't pull it in until it was 15 to 20 below.

 

#iworkforGM 

[cdnSpinalTap]

I understand they will start at those temps, but is it better for the vehicle to have them plugged in when the temp is that low?

[redwngr]

We can argue about  what temp might make it 'better', but the diesel supplement suggestion is that the heater be used below 0F. 

 

10 or 15 minutes with the elevated idle doing its thing (be sure it's enabled in the menu's) will warm both the engine and transmission nicely when cold started.  (Also gives a chance to clear the snow/ice/frost from the windows) 

 

Mine live outside, are never plugged in and get started/operated every morning.  Usually get a week or so of -5F to 0F range overnight with 10F or less daytime highs. And lots of 5 to 15F overnights. 

 

FWIW,  I'm certainly not against block heaters -- but don't think these trucks need it to be used at the temps 'here'.  

I use them regularly on other diesel equipped machines here that do get plugged in when they needed to be started below about +20 to +25F range.

 

 

[Sask Farmboy]

Like redwngr said, it is a debatable issue and comes down to personal preference based on experience and facts -- I'll give both here, but these are just my opinions.

 

I live in southern Canada, have worked in temps from -70F to +108F and I plug mine in whenever the temps are below freezing.

I have always cut out the temp switches on my OEM block heater cords so that I can decide at what temp the block heater operates.

Around here, fire trucks, ambulances and standby generators are parked inside and plugged in 24/7/365 mainly because they need to go at full throttle at a moment's notice.

They are left plugged in for a few reasons and one reason is to keep the pistons expanded out as close to norm operating temp as possible to reduce piston slap/piston collapse as much as possible.

Most engine wear occurs when the engine is started up and operated cold.

 

The con's -- it is extra hassle to plug in/un-plug and the cost of electricity.

When I worked as a mechanic (HD & Auto) at a Chev dealer, I was fortunate enough to work with a 30+ year Chev mechanic -- one of the best mechanics I have ever worked with.

Along with the above opinions, he also said that, way back in the day, during engine overhauls, the most cylinder wear was where the block heater was situated.

The reasoning was that the extra heat dried the cylinder oil off in that area when the block heater was operating, causing extra wear (on startup and warmup) in that area until the splash lube could get that area properly lubricated again -- not sure if that is still an issue with synthetic oils we use now.

That was one reason that, when we had to plug in vehicles and equipment all the time in winter, we installed recirculating block heaters which worked better all around.

 

So that's what I do, but that is JMHO.

 

Your best bet is to also consider all the other valuable, experienced opinions on this great forum.