Gel Temp for winterized diesel?

jonny mac

Well-known member
Joined
Aug 27, 2007
Location
Denver, CO
TDI
2002 Jetta Wagon
I line in Colorado and am wondering what the gel temp is for winterized diesel. I checked the FAQ's and it gave me this:

Winter fuel is less economical and lighter than heavier summer fuel. As the temperature drops further, some hydrocarbons continue to remain liquid, but others form wax. The net result of very low temperatures (-50F?) is that what was liquid fuel at +50F can resemble a thick gel. Further information on diesel fuel can be located at the following web site: www.chevron.com/prodserv/bulletin/diesel/L1_toc_rf.htm www.shell.ca/oshell/diesel.htm

Both links are dead and the gel temp of -50F seems pretty low to me. Is this right?
 

MethylEster

Veteran Member
Joined
Sep 16, 2004
Location
Lakeville, MN
TDI
Jetta, 1999.5. Red, 5 Spd
Winterized diesel gel points ( Pour Point ) varies with the season and area of the country.

For instance here in Minnesota in the depths of winter the diesel is good to -30 F. Some of the stations have a " special " winterized version that they say is good to -40 F. For comparison jet fuel is good to -60 F.

Winterized diesel will have varying amounts of kerosene added to lower the pour point accordingly. There are government regulations as to the specific requirements. As more kero is added your mileage will go down.
 

weedeater

Top Post Dawg
Joined
Mar 17, 2001
Location
Reston, VA
TDI
Jetta, 2001, Baltic Green
winterized diesel in Dallas will not be the same as in Denver. Nor will Denver be the same as Calgary.

Where I am, it's safe to down around 0F (I think) cuz it doesn't get that cold here. But if I filled my tank and decided to drive up to Toronto in the middle of winter, I'd be in trouble.
 

rotarykid

Top Post Dawg
Joined
Apr 27, 2003
Location
Piedmont of N.C. & the plains of Colorado
TDI
1997 Passat TDI White,99.5 Blue Jetta TDI
10 * C or lower in the fall or spring TREAT IT !!! Especially the FALL

A rule of thumb I've lived by for 30 years in the spring & fall is if it going to get below 10 * C ( 50 * F ) for any period of time treat your fuel . During the winter you are more than likely ok unless you get some severe cold below what your region usually sees .

But I always keep my fuel treated year round to help keep the fuel system clean of algee & bacteria which both love diesel fuel .


If you have any BD in the mix treat the fuel and dilute it with petro diesel below that 10 * C mark .

Below a sustained 0 * C ( 32 * F ) keep BD % below 30 % treat it double dose .

I had some 50 % BD gel up on me last fall on I-70 in Utah and it was treated .
 

jonny mac

Well-known member
Joined
Aug 27, 2007
Location
Denver, CO
TDI
2002 Jetta Wagon
I found some data as shown below with gel temp in F :

bio % wint diesel % gel temp
10 90 2
20 80 4
30 70 6
40 60 8
50 50 10
60 40 13
70 30 17
80 20 21
90 10 25
100 0 32
bio % kerosene gel temp
10 90 -28
20 80 -23
30 70 -17
40 60 -11
50 50 -5
60 40 2
70 30 9
80 20 16
90 10 24
100 0 32

The data says that if i use 90% bio and 10% winterized diesel I am good to 2 degrees F. I can achieve the same min temp using 60% bio and 40% kerosene. This leads me to believe that the gel temp of winterized diesel is around 0 degrees F. But you guys are telling me that the winterized diesel should be good to -30 or -40F???? Is this only good for minnesota or also in Colorado....we get some cold weather.

I am trying to decide if I should blend with kerosene or diesel.
 
Last edited:

Lug_Nut

TDIClub Enthusiast, Pre-Forum Veteran Member
Joined
Jun 20, 1998
Location
Sterling, Massachusetts. USA
TDI
idi: 1988 Bolens DGT1700H, the other oil burner: 1967 Saab Sonett II two stroke
Different raw oils result in different gel temperatures from the biodiesel produced from those feedstocks.
B100 from a supplier that uses virgin soy oil had a gel temperature of about 25F. I could and did run B100 at 27F with that suplier's fuel.
My present supplier uses re-claimed cooking oil for the base from which they produce their biodiesel. This biodiesel has a gel temperature of about 32F.
A 50/50 blend of -40 gel diesel and +25F gel bio will have a gel of about -15F. The same 50/50 blend but with +32F bio will have a gel of about -8F.
Do some freeze thaw tests with your own bio to determine where it becomes too thick to be used and treat it accordingly.
 

scooperhsd

Top Post Dawg
Joined
Aug 19, 2003
Location
Kansas City KS
TDI
NB, 2000, RED(5 Speed conversion) 2015 Golf SE
In general - you're worrying too much about it.

Your local stations will get their fuel from a local distributor, who orders it based on the time of the year. If you feel that is not enough, I have used PowerService in the white bottle to lower it an extra 20 degrees or more (I usually use 8 oz / tank). I can honestly say I've never had a gell problem.

I also use some common sense. If you looked at that fuel chart in the FAQ, you would notice that as you go further north, the gel points are lower. With a TDI's 600+ mile range, you could drive from Jacksonville FL to Washington DC, or from DC to Boston, on one tank ! To counter this, if you're on such a trip - make sure you fill up with LOCAL fuel BEFORE you shutdown for the night.
 

mrGutWrench

Top Post Dawg
Joined
Aug 29, 2002
Location
Carrboro, NC
TDI
'03 Jetta Wagon, 5-speed, 563K Miles (July '23)
scooperhsd said:
In general - you're worrying too much about it. (snip)
__. Yeah, you're right but what he didn't mention in his first post is that he's trying to figure how to blend bio himself. In a wind-swept, high altitude place like CO, that's a bigger factor.

__. I think he should blend his fuel ... and carry a warm coat, boots, a "space blanket" and flares. He's gonna need them.
 

jonny mac

Well-known member
Joined
Aug 27, 2007
Location
Denver, CO
TDI
2002 Jetta Wagon
I used 60% bio and 40% kerosene last year and never had a gel problem, but the only kerosene I could find in this area is off-road kerosene and is red. Since i used it on the road it IS illegal and so I am looking for an alternative this year and would also like to know the facts. I also want to run the highest percentage of biodiesel possible thru the winter. Very often, my biodiesel homebrew is pretty red to begin with so it looks like the off-road kerosene, but it would be nice to be legit. If the winterized diesel was actually good to -30F then I would use that instead of kerosene.

According to BKmetz, the winterized diesel's pour temp decreases as we move into the colder months. I need to winterize my bio before the temps decrease and I won't be able to get the "cold" winterized diesel unitl January or so.

>>>I think i am just going to go kerosene again this year.

Thanks for the discussion, sorry for the long thread. Now I know.
 

rotarykid

Top Post Dawg
Joined
Apr 27, 2003
Location
Piedmont of N.C. & the plains of Colorado
TDI
1997 Passat TDI White,99.5 Blue Jetta TDI
jonny mac said:
I used 60% bio and 40% kerosene last year and never had a gel problem, but the only kerosene I could find in this area is off-road kerosene and is red. Since i used it on the road it IS illegal and so I am looking for an alternative this year and would also like to know the facts. I also want to run the highest percentage of biodiesel possible thru the winter. Very often, my biodiesel homebrew is pretty red to begin with so it looks like the off-road kerosene, but it would be nice to be legit. If the winterized diesel was actually good to -30F then I would use that instead of kerosene.

According to BKmetz, the winterized diesel's pour temp decreases as we move into the colder months. I need to winterize my bio before the temps decrease and I won't be able to get the "cold" winterized diesel until January or so.

>>>I think i am just going to go kerosene again this year.

Thanks for the discussion, sorry for the long thread. Now I know.
You can use off road as an additive only , no more than 10 % of the mix . You go beyond that 10 % point and get caught it's a $10,000 fine for first offense .

A perfect example of getting into trouble gel wise is ;

You fuel up with D2 on the front range today and drive up into the high country with untreated fuel . You do this today with summer fuel still in front range pumps more than likely your fuel will gel up in the overnight up at high altitude in their lower overnight temps this time of year . You do this in the middle of winter there would be no issues as all the fuel sold in region is treated to deal with the high country's low temps . There are areas up there already breaking the freezing mark nightly , it was below freezing in the high country back in the second week of August .
 

GdB

Veteran Member
Joined
Sep 5, 2005
Location
Cypress, California, USA
TDI
Golf IV swap 2002
BKmetz said:
ASTM pour point tables for winter diesel.
http://tdiclub.com/TDIFAQ/TDiFAQ-10.html
:)
That link is informative, but way out of date. CFPP was replaced by LTFT (low-temperature flow test) in the US.

See http://books.google.com/books?id=6vVlr6j06pAC&pg=PA14&lpg=PA14&dq=california+diesel+CFPP&source=web&ots=I_eKHkDZ6n&sig=UN_sEatKKDrGsw5iPuNHK7BvjeI&hl=en&sa=X&oi=book_result&resnum=2&ct=result#PPA15,M1

Here is some more up to date info on LTFT http://www.biotenn.org/media/ColdFlowPerformanceSummary.pdf

Skimming through it, it appears that cloud point is a few degrees higher than LTFT temperature.

I'm going for SoCal to Sierra Nevada mountains on half a tank, so I am just going to follow the " [FONT=&quot]make sure you fill up with LOCAL fuel BEFORE you shutdown for the night[/FONT]" rule.
 

N4teTheGreat

Well-known member
Joined
Dec 1, 2007
Location
San Francisco, CA
TDI
2004 Golf TDI
I've not had a problem with my car in the winter, I just keep a white bottle of power service with me and add the required amount at each fill-up. I've left my car out in the snow all day while skiing in the mountains and it fires up right away when I get back. I do always make sure I have a full (ish) tank if it's going to be really cold to avoid condensation.
 
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