At what temperature do you add winterizer to your diesel tanks?

If your last serious tank of diesel was purchased up north -- it's likely you don't need to do anything.

But if you bought diesel down south -- you might wanna treat your fuel if/when you expect temps to fall below 15 degrees F.

-- L

 

I did once. Never again.

I added it and in a very short time the truck would not run.
All the fuel filters were filled with ice.
Probably would have been better if I had added it when the temp was warmer, but at that temp it just made things worse.

If it is cold enough to gel the fuel I'll just keep it idling.

 

Anything below 20.

 

Fuel can gel at temps as high as 35 degrees, it all depends on a number of factors. Most fuel is treated starting in late September in the northern most regions, moving south as the weeks pass. Still don’t trust the fuel to be properly treated. Most additives that are found in the truck stops and auto parts stores are rated for up to -20. Make sure to read the label for the rating and the number of gallons it will treat. Add the treatment to the tank, then fuel. It will mix with the fuel quickly this way.
The question to treat or not. Have never had a problem when adding fuel treatment. No performance problems, no cold plugging. Nothing. So did it work? Have no way to know for sure. Did make me a bit more comfortable that I wouldn’t have problems.

The bigger problem is actually DEF. Since it is 70 water, stored as a small quantity in a plastic tank. It will freeze long before you have a fuel problem. The DEF system does have heating elements in the tanks.
Little known thing about that. By emissions laws, it has 90 minutes to heat the fluid to a usable temperature.

 

Gotta add before that happens

 

If it makes you feel good do it. I did I feel better knowing it’s in there. When I’m back on the road, it’s a split. But I’ll probably add some to the tanks. Company pays for it and I feel better knowing I did all i could.

 

You realize you can treat the fuel all you like but if your fuel filters or water separator are not clean your gona have gelling problems

 

A lot of drivers are running Davco separators with electric heaters and don't know it. They get a rude awakening when the element fails and they gel up.

As someone who spent many years running the Dakota and Minnesota, southern fuel gets treated below 20F, northern fuel below 10F, and #1 enters the chat if the truck is getting shut off in below 0F temps, or running in -10F or lower.

Exposure time plays a part as well. If I've got full tanks and know I'm only going to see treatable temps for a couple hours, I don't worry too much, I know the heater will take care of it. Lower fuel levels or longer exposures dictate treating as needed.

 

On the old trucks you learned a few tricks.
Last year i was running -27 and still going 60-65 mph. can imagine the wind chill.
Most froze up, i even had oil change done at a speedco at that temp.
30 trucks got fuel filters/additive PS/Howed and even Lucas.

I order to house every year a case of FPPF polar power(older drivers will remember it) and i’ll even buy some rubber bands and diapers and put that around fuel filters for “extra insulation”

After they changed oil, mine fired up, and i drove on, unloaded, made it to reload and back down.
Even fuel at Hoods was gelled up and not wanting to pump, plus their heater had frozen in restaurant.

Topped off, added another quart, kept riding.

47 was count of trucks on side of road, presumably gelled.