Skip to content


Diesel fuel is impacted by seasonal temperature changes. Conventional summer diesel fuel can begin to gel around 32°F. If blended with biodiesel, it will begin to gel at higher temperatures. Some biodiesels begin gelling in the upper 40s to low 50s. So preparing your fuel before temperatures drop is important and will help mitigate potential cold temperature issues.

What happens to diesel fuel in cold temperatures?

Untreated diesel freezes. Diesel fuel contains paraffin, a naturally occuring wax. When temperatures drop, the tiny wax molecules gel together, forming filter plugging crystal blocks. Under normal, non-winter, temperatures paraffin wax adds power and lubricity to diesel fuel. In cold weather, they drop out of the fuel and gel together, preventing fuel from flowing through filters and the fuel system. Without cold flow improvers, engine failure is certain.

Four Points of Reference to Know about Diesel Fuel Gelling

  1. Cloud point is first observed by cloudy fuel. It is the point at which the first crystals form in the fuel when wax begins to clump together.
  2. Cold Filter Plug Point (CFPP) is the lowest temperature diesel fuel can pass through the filter without clogging. This is the most referenced metric because it represents the point when engine operations fail.
  3. Pour point is the lowest temperature diesel fuel can flow before freezing.
  4. Gel point is the temperature diesel becomes solid and is no longer capable of flowing.
Gelled Diesel Fuel Clogging Filter

How do you prevent diesel fuel gelling?

Cold winter temperatures do present a challenge. Putting a winterizing plan in place is a good first step to overcoming temperature related issues. Treat your fuel with winterizing additives. Biobor DC+Cetane Winter Blend is a good place to start. It is the perfect multifunctional additive with cold flow improvers. Cold Filter Plugging Point (CFPP) is reduced by up to 30⁰F at regular treat rates. Pour point is reduced and icing is prevented helping to reduce ice related filter blockages. Looking for a simple winterizing additive, use Biobor Coldflo with Lubribor. It is a concentrated diesel fuel additive formulated to provide superior cold weather operability and engine protection.

Follow Biobor

Share the Post

Leave a Reply

Your email address will not be published. Required fields are marked *