I do believe most of the Duramax's have a heater built in the head-unit of the fuel filter. In my personal opinion I think the engine compartment stays relatively warm and helps.


About your question reguarding blended or unblended fuel. How much fuel do you store? How often is it refilled? I know the fuel up here has an additive already put in it at the pumps. I would guess that all fuel companies would have an additive put into their fuels before it is brought to gas stations in colder climates to prevent gel from forming. I have never added any additives to my fuel. I feel comfortable with this, only because I get my fuel on a military installation and I know how strict they are on keeping filters changed out and testing the fuels they receive. To answer your question on how low the temp can go before additives, well, my truck as been in -50 degrees and never missed a beat. Keep the filter changed regularly and enjoy the Duramax.


The biggest change I have made to my duramax for cold weather is changing the oils to synthetic. After I changed my oil over to Mobil Delvac 1 I have noticed that my engine runs smooth even at extreme low temps. I used to run Valvoline 15-40 and if the temps were below 10 degrees when I started the truck up it was very loud. Now, it is just about as quiet at a 0 degree start as what it is at a 60 degree start.





Jeff

 

Its common practice to use an additive. GM also allows mixing the fuel with kerosene for those extremely cold times. But, your right, you will get a noticable loss of power if you do. IMHO, the easiest way to combat possible problems is using a quality additive. It has alot of other benifits also.

 

In regard to refining, the fuel we're using is Cenex's "premium" diesel fuel. It's stored in a 2000 gal tank that is filled about 2-3 times/year.


As far as anti-gel additives, I know they are included in some winter deliveries, but we usually don't order fuel in the winter. I know we are running non-winter fuel, because on cold days it gels in the filter on the bulk fuel tank.


The -50 is really interesting. That must be pushing the temp where a 60/40 blend would gel!

 

... To answer your question on how low the temp can go before additives, well, my truck as been in -50 degrees and never missed a beat. Keep the filter changed regularly and enjoy the Duramax.

I'm assuming that was a mixed blend of diesel. Around here, they just start mixing it, and we never know when they are mixing unless you ask them, or you watch the price go up.


My parents had one of those 350 diesel Olds 88's in the mid 80's that gelled on them when the temperature was around 0. Fuel will definitely be gelled at -50 if it's not mixed with #1 or has some additive in it.


I used to by my fuel from a local guy here, and he always told me that #2 would only go down RELIABLY to about 20. If it was going to be below that for any length of time, he was mixing. The colder it got, the stronger he mixed it. I think that it will probably go lower than that, but it never hurts to be safe, because gelled fuel SUCKS!!!


CADman_ks

 

I am pretty sure the fuel was mixed well. I used my truck up in Fairbanks Alaska and it was very cold up there a couple weeks ago. Here in Anchorage it is in the single digits and I know they have additives in the fuel. I can tell when they start mixing it, I really lose on my gas mileage.


Jeff

 

I am pretty sure the fuel was mixed well. ... I can tell when they start mixing it, I really lose on my gas mileage.

The mileage is the first thing to go.

Around here it usually pretty obvious when they start mixing because the price all of the sudden goes up. Typically about .05/gal...


CADman_ks

 

Well, I have been here 3 years now and the fuel price has stayed about the same the entire time. I guess the fuel up here stays mixed all year round...

 

Instead of blending just use a winter fuel additive such as Primrose 409. It will lower the cloud point 30 degrees, provide increased performance (instead of the decrease associated with blending), minimize free water (and its freezing), keep the injectors clean, etc.
There are other products which will accomplish the same end. Very inexpensive and yet provides effective insurance against getting caught in the middle of nowhere with a clogged fuel filter.
The unfortunate aspect of diesel fuel cloud is that it does not occur immediately on start-up. The engine will start and run fine, until the ice crystals clog the filter which may take as long as 15 to 20 minutes. Enough to get far enough down the road to be a major inconvenience.
Fuel additization is more foolproof, has many added performance benefits and has no downside.
George Morrison

 

We don't have a choice of blended or unblended here in Utah. The refinery starts shipping blended in early Oct. I average mileage goes down 1 MPG. No big deal. I personally would not put fuel in my truck that came out of a bulk farm tank. None of our local farmers do. They fuel in town. Later! Frank

 

Hey!


When I said I was burning fuel from a farm tank, I didn't say it was red.


I'm burning truck fuel that is subject to all taxes, etc. While there is some risk of tank gunk, the only time I've had issues is after fueling at EZ-stop.


We're heading into some cold weather here (not by fairbanks standards, but cold enough to cloud fuel) so I'm going to do some testing on the gelling issue.