Engine/Transmission (1994 - 1998) how cold for #2

[Berrigan]

Was just woundering if any TDR members with frost on there mustaches know how cold you can safely go with straight number 2 diesel. I would be most interested in non garaged situations where the truck sits out all night with no suplimental block heat, etc. When would geling start to be a problem and if no #1 is available, what additives do you recommend. thanks Bill

 

[woodsrat]

not sure about where you live but all of our fuel suppliers put additives in the fuel(winter mix) when it starts turning cold. I dont add anything to our fuel(26 trucks) and cant remember the last time we had a gelling problem.

 

[JFaughn]

Being from AZ they may not have a winter mix but I do not know, here in MN. they have winter blend unlessyou go to the truck stops to get #2 and put in antigel aditive , and it kind of depends on not only how cold [ 20* and colder] also how long will it sit in what temp. , but for winter diesel starting in general a warm eng. [ plug in] and good batteries[ when batteries get to 0 degs. they only have about 20% capacity left] are problums long before geling , then if driving in sub 0 for long periods can gel .

 

[bmoeller]

We've only had gelling problems with one truckstop here, with the semi trucks. They only mix in a 30% blend of #1, not 50/50 or so. If we add additives (Howes) with that fuel though, we don't have a problem with it.

----------------------------------------



http://www.filtercouncil.org/techdata/faqs/faqdieselfuel.htm



Q: What is the "cloud point" of diesel fuel and why is it important to filtration?



A: #2 diesel fuel has a wax component that contributes to the lubricity and heat value of the fuel. The "cloud point" refers to the temperature when the wax precipitates out of the fuel in the form of small wax crystals. Different fuel blends can have very different cloud point temperatures, generally ranging from -10°F to +40°F. #1 diesel fuel does not contain large amounts of wax, and therefore does not have a noticeable cloud point. Diesel fuel distributors blend local diesel fuel supplies so that the cloud point is usually not reached. However, if ambient temperatures fall below the cloud point of the fuel on a vehicle, the precipitated wax crystals can quickly coat and plug a filter element.



To avoid filter wax plugging and loss of engine power, diesel fuel filter systems are often supplied with an auxiliary fuel heating or return fuel heat recovery systems. Fuel additives are also available that modify the formation of wax crystals, making them less likely to plug the filter.

 

[SDrake]

The problem does not just occur with starting. You can be going down the highway with a warm truck and gelling will occur leaving you helpless. Straight #2 will gell at 0 deg F. I know that for sure. It depends on the particular batch of fuel, the particular truck, etc. If I have any idea it is going to be as low as 10 degrees I put in the fuel treatment. You may hit a colder spot somewhere on the road and there is no forgiveness. I think fuels are a little better today but the batches do vary. I am not big on pushing for just how close I can come without having a problem. It is no fun. Just put in the antigel.

 

[JJW_ND]

+5 to -5 would be my guess.

You can get straight #2 all winter even in ND that will gell if untreated. But if treated with either blending at the pumps with #1 or adding additive it works fine. I have NOT used any blend or #1 in the last 9 years. I rely on Stanadyne or Amalgamated. My truck is garaged at night, but sits out all day and an occasional night over the weekend.



I can only speak for 94 - 98 12V but would guess even the newer trucks would perform similarly regarding gelling after you have a warmed up truck. Our engines return alot of fuel to the tank. This in addition to the heater in the fuel filter gives alot of winter protection. Much more then Fords or Chevys of the same years. This returning heated fuel might not WARM the fuel but it sure keeps it from cooling off very much. I have driven thousands of miles with untreated #2 through sub zero temps down to as low as -35 and never had any trouble. After "getting luckly" so many times I quit treating the fuel on the longer trips from souther climates back to ND when driving straight through. This only applies if you only shut down for no more then a couple hours and start out with underground "warm" fuel. Basically, the fuel never gets a chance to cool off enough to cause a problem.



Here in Bismack, the temperature at which I get nervous and start treating is when daytime temps stay below 5 above.



Never a "gelling" moment with 18,000 gallons used so far.



jjw

ND

 

[Berrigan]

Thanks for the replies. I live in the warm part of Arizona but we just bought a cabin in northern Az. The elevation is aout 6600 feet. I did a climate search for the area and the results were, normal average low winter temp +14F, record low winter temp -25F. Acouple days ago the low was +2F. It doesnt have a garage. I think I will use additives. One last question, will these wax crystals that plug the filter melt or reliquify when warmed back up? Or do they stay on the filter and force you to change it. Thanks again, Bill

 

[SDrake]

My answer would have been the same as JJW ND's until the day mine gelled. When I left the house my thermometer was saying 0 deg but the temp was dropping and I didn't know that. But it may have been as low as -10 out on the road as was being reported 30 Miles away but I think it was closer to 0 where it jelled on the run. I had been driving in similar weather on trips in Ohio numerous times and I just decided all this fuss about jelling was not worth paying attention to because of how our trucks are built with the fuel returned, the heater etc. The cross winds were high so that may have done some extra cooling in the lines.



I just don't want to go through that again. I treat the fuel when it gets cold. Russian roulette with the fuel batches is not my idea of fun.

 

[JFaughn]

Once the fuel is warmed up the wax will melt again , so the additive is something that should be there all the time reguardless , becouse of the lack of lube in the fuel these days and weather or not the refinree or the fuel station remembers to put in that day or what ever , its our trucks and we are the last one to pass the buck and the first one to have to pay , so its a mater of preventive maintance . now to be able to buy in bulk.

 

[Champane Flight]

Winter blends

Diesel batchs from refineries vary in freeze points, all depending on destination of the fuel sold. For example Texas refinery shipping fuel to Colorado has a blend to -10 to -15 pour point. Some jobbers like to blend at the rack or terminal, they will go anywhere from 25% #1, to 75% #1, depending on thier last winters temps, and what their customers want. This is on top of what the refinery does, this to me is a witches brew. I try to stay away from #1 blends in the winter, unless temps get to -20, -50 for extended periods. They reduce power, and mileage. I use Amzoil cetane booster at a rate of 50ml per tankfull, and try to keep my tanks on the upper half. If I know my truck is going to be parked for awhile, I top it off. I also try to hold down short runs in the winter, where the truck never warms up before destination.



My truck has started (without being plugged in) in -35 weather after being parked for a couple of days. I did cycle the heater grids twice, and it did not like it much (sounded like a old washing machine)... . :-laf



Oh, by the way, I work for a major oil company, don't blame me for prices. just quality... .

 

[Berrigan]

Thanks for the info guys

Bill