How to Keep Diesel From Gelling This Winter: A Fleet Guide to Anti-Gel Additives

Every winter, the first cold snap in the Northeast leaves trucks stuck in yards with fuel that will not flow. Diesel gelling is one of the most common — and most preventable — causes of winter downtime. Here is what causes it, how to prevent it, and what to keep on hand.

What is diesel gelling?

Diesel fuel contains paraffin wax. When temperatures fall, that wax starts to form crystals and the fuel turns cloudy (the "cloud point"). Keep dropping and the crystals clump together until the fuel thickens into a gel that clogs fuel filters and lines. The exact temperature depends on the fuel blend, but untreated #2 diesel can begin to cloud well before it feels like deep winter.

The result is the same every time: hard starts, power loss, plugged filters and trucks that will not leave the yard.

Treat the fuel before the cold arrives

Anti-gel additives work by changing how wax crystals form, so they stay small enough to pass through the filter. The key point: anti-gel must be added before the fuel gets cold. It prevents gelling — it does not reverse it.

Best practices for fleets and owner-operators:

• Start treating in October, before the first overnight freeze.
• Add the additive to the tank before fueling, so the incoming diesel mixes it in.
• Follow the treat ratio on the bottle — more is not better.
• Treat every fill-up through the winter, not just the first one.
• Keep a spare fuel filter and water separator in every truck. Water in fuel can freeze and block filters too.

Which additive should you use?

We stock the brands fleets and shops ask for most:

• Power Service Diesel Fuel Supplement + Cetane Boost — winter anti-gel with cetane improver for easier cold starts.
• Power Service Diesel 9-1-1 — the emergency product for fuel that has already gelled. Every truck should carry a bottle from November to March.
• Howes Diesel Treat — a popular conditioner and anti-gel for heavy-duty fleets.
• Power Service Diesel Kleen + Cetane Boost — for warmer months, cleaning injectors and improving performance.

Shop the full range in our Fuel Additives collection and Winter Supplies collection.

What to do if your diesel has already gelled

1. Do not keep cranking the engine — you can damage the starter and batteries.
2. Move the truck somewhere warmer if possible, or warm the fuel filter area.
3. Add a de-gelling product such as Diesel 9-1-1 to the tank and the fuel filter, following the label.
4. Replace the fuel filter if it is plugged with wax.
5. Once running, treat the tank with a regular anti-gel to stop it happening again.

Stock up before the rush

Anti-gel sells out fast once the first cold front hits. RPS Distributors supplies fleets, repair shops and gas stations across New Jersey and the tri-state area at wholesale pricing.

Request a wholesale quote or call 1-855-498-7509 to order winter fuel additives by the case.