Diesel Fuel Gelling

[Matthew Harger]

Its been around or slightly below freezing in my part of the SF Bay Area last couple nights....from reading up on diesel fuel gelling it would appear that I've got no concerns with gelling and probably never will unless we go somewhere colder....accurate ??

[David T. Richelderfer]

I found this using a Google search:

"The Cloud Point is the temperature at which paraffin, which is naturally present
in #2 diesel fuel, begins to form cloudy wax crystals. When the fuel temperature
reaches the cloud point, these wax crystals flowing with the fuel coat the filter
element and quickly reduce the fuel flow, starving the engine. Typical cloud point
temperatures range from:  -18°F (-28°C) to +20°F (-7°C), but may occasionally
be as high as +40°F (4.4°C).  #1 diesel fuel (or kerosene) contains very little
paraffin, and therefore has cloud and pour points near -40°F (-40°C)."

There is more to read at this site.  If you want to read more, then go here:  http://www.todaystrucking.com/images/SolvingWinterDieselProblems91-1R2.pdf

It appears from my Google search there is considerable reading material if you wish to spend the time.  Another suggestion might be to ask a local retailer of #2 diesel what the "cloud point" is for diesel sold in your area.  In Eastern Oregon where I was born and raised and worked for most of my career, diesel and heating oils were routinely winterized from early Fall through late Winter.

[Dick Simonis]

Depending on where and when you last fueled you may already have a winter blend.

[Jeff Watt]

Up here in the Great White North (for reference look up Bob and Doug McKnezie from years ago on SNL or Second City) diesel is switched to winter blend usually sometime in October. Since we don't have 2 grades, I.e. #1 and #2 to choose from it is somewhat simpler as we can't put in the wrong grade In the winter. Stating that it may be at different times in the milder climates of S. Ontario and lower BC. Winter diesel may even have different standards in these locations. A relative in S. Ontario with a trucking company had problems a few years back when the diesel he had on site was only blended to about -18c (0F) and he had trucks not running because it was colder.

Since there are two grade in the US, I annually have to refresh my memory which grade to use when I leave home in the winter and fuel up in eg.  South Dakota. I carry a bottle of Diesel 911 just in case I get the wrong fuel and it starts to gel - haven't had to use it in the coach yet but I know it works from other diesels I've run.

[Matthew Harger]

Thanks everyone....looks like im probably good as long as I stay in my home area until the next ice age hits....I don't think the Bay Area has hit -18 in recent recorded history....

[David T. Richelderfer]

Something else that I just learned that is pertinent... California has biodiesel percentage requirements, I am told.  Biodiesel blends have a higher temperature cloud points due to glycerin from the bio having a higher temperature cloud point versus paraffin wax found in fossil diesel.  Soooo... the more bio percentage in the diesel blend, the higher the percentage of glycerin and thus, the higher I would suspect the cloud point temperature.  This leads me to speculate if fossil diesel starts to cloud at say, 20F, then a blend of bio and fossil diesel could be the reason for the higher cloud points of up to 40F found in my earlier post.  I don't know... but it sounds logical.