Skip to Content

What Temp Does Diesel Gel? How to Avoid Thickening Fuel

We have learned the hard way over the years that diesel fuel is no good in a deep freeze without some help. What does this mean, and what is too cold for diesel? Let’s take a look.

What is Diesel Gelling?

Diesel fuel starts to gel when temperatures are below its cloud point, typically between 32°F (0°C) and 14°F (-10°C). The cloud point refers to the crystallization of wax materials in the fuel. As these crystals form, the substance begins to appear cloudy. The crystallization worsens as the temperatures drop.

Unfortunately, there’s no exact temperature when diesel gels. It varies significantly on the environmental conditions, the blend of fuel, and if it contains any additives. However, if you live in a colder climate, you must take precautions to avoid it.

Typically, service stations in these areas switch to winter blends. These blends contain special additives that reduce the gel point. With these unique formulas, you can worry less about your fuel thickening but the blend can drop the gel point anywhere from 0F to -30F. Thus, if you will be seeing extreme cold, the addition of additional anti-gel is critical.

Diesel gelling at pump
No diesel is not black like this, but it does get sticky in the cold

Suggested Reading: Learn if you need to bulletproof your diesel engine.

Why Does Diesel Gel?

Paraffin wax is a component you’ll naturally find in crude oil, which is essential for creating diesel fuel. While refining purifies diesel fuel, some of these wax molecules can remain. In normal deisel #2 there is quite a bit of this wax in suspension.

At higher temperatures, these wax molecules stay in their liquid state. However, once the temp drops, they’ll solidify and form into crystals in your diesel fuel, making it gel.

The crystals combine, creating a gel-like consistency. As this occurs, the fuel loses its fluidity and begins to thicken and expand. This process can occur anywhere in your fuel system and wreaks havoc on your fuel lines, filters, and tank.

Explaining Why Diesel Fuel Gels and How to Use Diesel Winter Anti-Gel

Can Diesel Freeze?

Diesel can kind of freeze. Like mentioned before the wax turns solid and basically freezes, but this is only part of the fuel. The other hydrocarbon components will not freeze like that however until extreme cold south of -100F. So no, you should never find your solid diesel cans frozen but gelled up is common.

Pro Tip: Learn helpful tips for overlanding in the winter with a diesel engine.

what temp does diesel gel
Taking care of your diesel engine is extremely important to ensure its longevity.

How to Prevent Diesel Fuel From Gelling

If you want your diesel vehicle to run for a long time, you must take care of it. Gelling is one of the biggest threats to your car, especially during winter. Taking the necessary precautions can drastically reduce the chances of the temp making your diesel fuel gel.

Use Additives

One of the best ways to prevent diesel fuel from gelling is to use additives. Products like Hot Shot’s or Howes are some of the best in the industry. These change the molecular structure of your fuel and make it more resistant to gelling. We have used both these products with great success for both winter use and vehicle storage.

Think of the additives as medicine for your vehicle. You’ll adjust the dosage by the size of your fuel tank. Adding some additives each time you pull up to the pump is best. However, only add the appropriate amount based on how much fuel you need to fill your tank. You can then add your fuel, and it will combine with the additives.

While they’re pretty standard, always confirm any products are compatible with your vehicle beforehand. 

Howes Diesel Treat 64-Ounce Anti-Gel and Diesel…
This has been my go to for long term storage and anti gel for years. It seems to work very well.

Fill with Winter Formula Fuel

Most fuel stations in regions that experience extreme weather will switch to a winter formula. These formulas can withstand colder temperatures and contain additives that help prevent gelling. A winter formula can typically withstand sub-zero conditions without the temp making your diesel fuel gel. 

Ask the station attendants if you’re unsure whether the fuel station uses a winter formula. However, depending on the attendant, they may not be aware. Remember, you can always put the additives in yourself. 

Store Vehicle Inside

While it may not always be possible, you can prevent diesel fuel from gelling by storing your vehicle inside. You can protect your fuel system by keeping it in a controlled environment away from the harsh winter conditions. This reduces the chances that crystals will develop in your diesel and lead to blockages.

Additionally, keeping your vehicle in a garage protects various other parts of your vehicle. This route can help protect your engine, batteries, and other sensitive components. Unfortunately, not everyone has the luxury of a garage or other heated storage space.

Suggested Reading: Underground storage for vehicles and RVs can be a secure and safe location year-round.

Don’t Let Old Man Winter Gel Your Diesel Fuel

It’s not the end of the world if you experience gelling in your diesel fuel, especially if you catch it early. The crystals will liquify once warmer temperatures return. Additionally, you can dump additives into your system to help break up the crystals. If you take the correct steps, Old Man Winter won’t stand a chance against your diesel fuel.

What precautions do you take for driving in winter conditions? Let us know in the comments! 

Become A Mortons On The Move Insider

Join 15,000+ other adventurers to receive educating, entertaining, and inspiring articles about RV Travel Destinations, RV Gear, and Off-Grid Living to jump-start your adventures today!

Also, join our Mortons on the Move Community discussion over on our Discord Server!

About Tom Morton

Tom, a Pacific Northwest native, is our technical genius. Born in Washington and raised in Alaska before settling in Michigan. He's the man who keeps our operation running, both figuratively and literally.

With a background in Electrical Engineering, Tom specializes in RV solar systems and lithium batteries. He made history as the first documented individual to use a Tesla battery module as an RV battery. Tom has personally assisted countless RVers with system installations and has educated thousands more through his videos and articles.

Cinematography is another of Tom's passions, showcased in his work on the Go North series. You can see his camera skills on display in The RVers TV show on Discovery Channel and PBS where he also stars as a co-host.

Tom's mechanical expertise extends beyond RVs to boats, planes, and all things mechanical. He's renowned for taking on maintenance and repair projects single-handedly and is often spotted underneath RVs, making him the technical backbone of our endeavors.

About Us

Sharing is caring!

John S.

Wednesday 7th of February 2024

Good article.

As a Canadian I know all about 'winter diesel' but have never used it as I'm smart enough (and lucky enough) to head to the southern desert when those fuels are needed.