By Norman Ford · Updated October 2026

Diesel anti-gel additive dosing calculator

Diesel in the tank or being added (gal)Label dose: ounces of additive (oz)From your product labelLabel dose: per this many gallons of diesel (gal)From your product label; doses often change with the expected low temperature#1 diesel share in a winter blend (0 if none) (%)Your fuel supplier sets blends for your region

RESULT · ANTI-GEL DOSE

Anti-gel dose result
Additive to add	24.0 oz (0.75 qt)
#1 diesel in the blend	0.0 gal
#2 diesel in the blend	120.0 gal

Add the additive before the fuel gels, ideally before filling so it mixes. It does not reverse fuel that has already gelled; follow the product's emergency instructions for that.

Show the math

Ounces = gallons x label ounces / label gallons
#1 gallons = total gallons x blend %
1 US fl oz = 29.57 mL

Running cold lanes this winter? We plan loads with extra time for weather, at 5% of gross.

Start dispatch

This diesel anti-gel additive dosing calculator returns how much additive to add for a given amount of diesel, using your product's label ratio, and the #1 and #2 diesel volumes for a winter blend.

Gelled diesel is one of the most avoidable winter breakdowns. As diesel cools, the paraffin wax in it starts to form crystals. First the fuel turns cloudy, then the crystals clog the fuel filter, and finally the fuel thickens until the engine starves. An anti-gel additive, added at the right dose before the cold hits, keeps the crystals small enough to pass through.

How it works

Ounces to add = gallons x label ounces / label gallons
#1 diesel in a blend = total gallons x blend percent
#2 diesel in a blend = total gallons - #1 gallons

Every product has its own ratio, and many list a stronger dose for colder temperatures. The calculator does not assume a brand. Read the label, enter its ratio, and enter your tank size or the gallons you are about to add.

A worked example

A truck takes on 120 gallons of diesel ahead of a cold front. The additive label says 1 ounce per 5 gallons for the expected temperature.

Additive: 120 x 1 / 5 = 24 ounces, about 0.75 quarts

If the supplier recommends a 20% #1 blend for the trip, that is 24 gallons of #1 and 96 gallons of #2. Many stations in cold regions already sell a winter blend, so check what is in the pump before blending yourself.

When to treat the fuel

Treat before the fuel gets cold. Additives work as the fuel cools, by changing how the wax crystals form, so they must be mixed in beforehand. The easiest way is to add the additive to the tank just before filling, so the incoming fuel mixes it. Treating a tank of fuel that is already cloudy or gelled will not fix it.

Cloud point and gel point

The cloud point is the temperature where wax crystals first appear and the fuel turns hazy. The cold filter plugging point is where crystals start to block a fuel filter. The pour point is where the fuel stops flowing. Number 2 diesel reaches these sooner than #1 diesel, which is why winter blends and additives exist. Fuel sold in cold regions in winter is often already treated or blended, but fuel bought in a warm state and carried north may not be.

Running from warm to cold

The highest risk is a truck that fuels in a warm region and drives into a cold snap. Its tank is full of fuel blended for warm weather. If the forecast on your route drops well below freezing, treat the tank before you leave and plan to fuel where winter blend is sold. Carry a spare fuel filter or two, and know how to change them.

Other winter fluids

Winter also affects other fluids. DEF can freeze, and trucks have tank heaters for it; our guide to DEF cost and usage per gallon of diesel covers cold-weather handling. Engine oil thickens in the cold, so check the viscosity your maker allows for winter; the semi truck oil capacity chart covers capacities.

Cost of treatment

Additive is a small cost per gallon, but it adds to your fuel bill in winter. If you track fuel per trip, the trip fuel cost calculator shows the diesel side, and the fuel surcharge calculator shows how a surcharge moves with diesel prices, which often rise in cold months.

Common mistakes

Treating after the fuel has already started to cloud.
Guessing the dose instead of reading the label for the expected temperature.
Forgetting the second tank on trucks with two.
Skipping a spare fuel filter on a winter trip.
Mixing products, or using an additive meant for another purpose.

Safety first

If the fuel gels on the road, get to a safe spot and do not run the batteries down cranking. Call for roadside help if you cannot get the fuel warm and flowing. A cold breakdown is a safety problem before it is a freight problem.

Where we fit

We plan winter loads with weather in mind and keep the broker informed when delays happen. We find and negotiate the load, you say yes, counter or no, and the broker sends the rate confirmation to you to sign. For one-truck operations, the owner-operators page lays out the details.

Questions

How much anti-gel do I put in diesel?

Follow the ratio on your product's label, which is usually given as ounces of additive per a number of gallons of diesel, and often changes with how cold it is expected to get. Enter that ratio and your tank size in the calculator. Adding more than the label calls for rarely helps and can waste money.

When should I add anti-gel to diesel?

Before the fuel gets cold, and ideally just before you fill so the incoming fuel mixes it through the tank. Anti-gel additives work by changing how wax crystals form as fuel cools, so they need to be in the fuel before it reaches its cloud point. They do not reverse fuel that has already gelled.

What is the difference between #1 and #2 diesel?

Number 2 diesel is the common grade for trucks and has more energy per gallon, but it starts to cloud and gel at higher temperatures. Number 1 diesel is lighter and stays liquid in colder weather, but has a little less energy. Many suppliers sell winter blends of the two, set for local conditions.

What do I do if my diesel gels?

Get the truck somewhere warm if you can, or use the emergency treatment some additive makers sell for gelled fuel, following its instructions. Fuel filters often clog first and may need replacing once the fuel is liquid again. Prevention is far easier: treat the fuel before the cold arrives and carry spare filters in winter.