What Temperature Will Diesel Freeze?

What is the temperature at which diesel fuel gels? That’s a tough question to answer because your diesel-powered vehicle won’t drive anywhere in the cold if you don’t prepare properly. Fortunately, the problem can be readily avoided by applying a gasoline additive, which can help stop gelling from happening in the first place. While it’s important to prepare your vehicle before the cold weather arrives, acting quickly can help you avoid a breakdown.

At What Temperature Does Diesel Fuel Gel?

When the temperature drops below 32 degrees Fahrenheit, the paraffin in diesel fuel begins to harden, clouding the fuel tank. This modification will not prevent you from driving, but it will serve as a reminder of how colder weather affects gasoline use.

Gelling happens when the temperature falls between 10 and 15 degrees Fahrenheit, blocking the gasoline tank and fuel lines. You may need to have your vehicle towed to a garage at this stage so that your mechanic may repair any damaged fuel lines and thaw the fuel tank.

How Do You Prevent Diesel Fuel From Gelling?

If you utilize a fuel additive, you can drive a diesel car in subzero temperatures. A fuel additive designed for diesel engines decreases the fuel pour point (the temperature at which it freezes) by as much as 40 degrees. It also inhibits gelling by dispersing water.

The crystals that form in diesel fuel during cold weather are altered by a diesel fuel additive. The additive lowers the size of the crystals in diesel fuel, preventing it from waxing or gelling. It alters the fuel’s chemical characteristics, allowing it to flow at temperatures considerably below zero degrees.

If the diesel has already gelled, an additive can help. To begin, empty the tank and disconnect the fuel line. Typically, this entails pouring the additive into the tank and waiting 20 minutes for it to break down the gel before starting the vehicle, but check any directions carefully to ensure you’re following the appropriate steps. Allowing your vehicle to idle for a few minutes will allow the fuel lines to clean.

Cold Weather Preparation

There are a few more things you can do to prepare your vehicle for cold weather besides utilizing a diesel fuel additive. First, make sure your battery is in good working order. When the weather turns cold after a hot summer, the battery is more vulnerable to failure. Replace your battery if the reading is less than 12.45 volts on a multimeter. You don’t want to have to deal with battery troubles on top of fuel issues.

Second, if temperatures are really low, an addition may not be sufficient. Keep in mind that an additive can reduce the pour point by up to 40 degrees. It can prevent blockage in temperatures as low as minus 30 degrees Fahrenheit. We all know that colder temperatures are feasible, and that the addition may become useless as a result. Even if the temperature does not drop that low, a block heater may be required, especially if you park outside. Make it a habit to turn on the block heater when the temperature drops below freezing.

You may avoid being stranded on even the coldest days if you take excellent care of your diesel vehicle and its gasoline.

NAPA Online has a comprehensive list of fuel additives, or visit one of our 17,000 NAPA AutoCare facilities for routine maintenance and repairs. Consult a trained specialist at your local NAPA AUTO PARTS shop for more information about diesel fuel.

How long does it take for diesel to freeze?

  • Gelling: It’s unusual to have a situation where the fuel practically turns to jelly. Gelling happens when the paraffin wax in diesel solidifies due to a drop in temperature, and the fuel’s temperature must be kept below minus 10 degrees F for extended periods of time, such as 48 to 72 hours. When diesel is cold soaked, the paraffin wax in the fuel hardens, giving it a hazy look. At temperatures as high as 32 degrees F, the fuel will begin to cloud, but it will continue to flow. Before the fuel can gel, it must be kept at a very low temperature for an extended period of time. It’s common to hear drivers complain about their fuel gelling up, but this is almost certainly not the issue they’re having. Ice or solidified paraffin wax in the fuel filter is more likely to be the issue. There’s more on that later.
  • Cloud Point: To determine the cloud point of a sample of diesel fuel, which is the temperature at which the naturally present paraffin wax in #2 diesel fuel begins to crystalize, there are prescribed methods. The fuel has a hazy look due to the microscopic particles of suspended hardened wax. Cloud point temperatures for diesel fuel typically vary from -18°F to +20°F, but can reach +40°F depending on a variety of factors connected to the base stock and refining operations. The cloud point of so-called winter diesel fuel (#1 diesel or kerosene) is substantially lower since it contains relatively little paraffin. Fuel distributors will test the product and, if requested, may include the results in tenders and delivery receipts.
  • The temperature at which a liquid loses its flow properties is known as the pour point. The pour point of diesel fuel changes according on the wax content in the fuel, which varies depending on the source of the base stock, the refining process, and the type and quantity of additives added to the fuel during refining or distribution. The difference between the cloud point and the pour point is always there, with the latter often being 2° to 20°F lower than the former. To establish the pour point of a fuel sample, certain tests must be performed. Bulk providers, as previously stated, can supply this information.
  • When diesel fuel is cooled, the cold filter plugging point is a measurement based on a standardized test that indicates the rate at which it will flow through a standardized filtration equipment in a given amount of time. The CFPP is the point at which the sample fails to pass through the filter in the time allotted.

Does diesel freeze in cold weather?

When temperatures drop, the bonds between diesel fuel molecules become more rigid, causing them to connect more tightly. The procedure is repeated until thin sheets of diesel are linked together, resulting in a waxy material in the fuel. A little cloudy appearance within the fluid may be the first sign. **

Enough of these wax pieces accumulate in fuel filters over time, clogging them and preventing fuel flow. If the process continues, the fuel may entirely gel, forming a waxy goo that is semi-solid. The fuel supply to the engine has been cut off, and the vehicle is unable to run!

In frigid conditions, the term “gelled” is used to describe unusable equipment. The wax creation process is aided by frozen water molecules in diesel fuel, which provide a template for the wax to develop on. Biodiesel blends tend to hold more water in suspension than other fuels, exacerbating the problem.

What do you add to diesel to stop it freezing?

Diesel fuel has a lot of advantages. More vehicle power means better fuel economy, but one of the main disadvantages of diesel fuel is that it performs poorly in cold weather. Diesel crystallizes when temperatures drop, clogging fuel filters and lines. This not only prevents engines from starting, but it can also result in costly repairs if the engines are damaged.

You should apply an anti-gel fuel supplement to keep diesel gasoline from gelling (or crystallizing). Anti-gel additives are simple to apply; simply add the remedy to your gasoline tank. Anti-gel additives lower diesel fuel’s freezing point, making it less prone to freeze in cold weather. Anti-gel additives are used to reduce the plugging point of cold filters (CFPP). The CFPP is the lowest temperature at which a filter will still allow fuel to flow through it.

The presence of wax in diesel fuel necessitates the addition of an anti-gel additive. Normally, wax is a liquid that dissolves in the fuel. The wax is the problem because it causes fuel to gel, and gelled fuel (or crystals) can clog engine fuel filters. If the temperature drops below a certain point, the engine will totally gel up and cease to function. So why don’t we just remove the wax and avoid the whole gelling issue? The wax component is there because it contributes to the fuel’s high cetane value. Cetane provides more power and improved engine response. In the winter, wax concentration is lower, but it is still present in diesel blends for cetane.

1. When the temperature drops below 32 degrees Fahrenheit.

It’s a good idea to start using anti-gel as soon as the temperature drops below freezing. As a general rule, the lower the temperature, the more gasoline additive is required. We recommend that you follow the anti-instructions gel’s on the bottle.

2. Sudden temperature dips

If the weather forecast predicts a cold front, you should prepare by applying additional anti-gel ingredient. The importance of preparation cannot be overstated. Anti-gel additives will not harm your engine, so use extra when in doubt.

3. When it comes to adding fuel

Whenever you fill up at the pump in the winter, use an anti-gel additive. Most additives can be put either before or after the fuel is added. To guarantee a good mixing, we like to add the ingredients ahead of time.

4. When the fuel starts to solidify

As soon as feasible, add an anti-gel ingredient. If your fuel has already gelled or your fuel lines are clogged, an emergency additive that dethaws fuel and de-ices filters is recommended. These emergency procedures re-liquify the fuel, making it combustible once more.

We provide a few anti-gel additives at Fuel OxTM as a precautionary step. We recommend that you use our Gasoline OxTM Cold Charge to prevent fuel gelling. We recommend utilizing our emergency fuel treatment, Fuel OxTM Heat Bomb, to restore the flow of frozen fuel lines if the fuel has already gelled. A little goes a long way with this product, as it does with all of ours; one ounce treats up to 80 gallons of fuel. A complete list of our winter anti-gel additives can be seen below:

At what temperature does number 2 diesel freeze?

The gel point of diesel or biodiesel fuel is the temperature at which it freezes solid and can no longer flow by gravity or be pumped through fuel lines. When a fuel reaches a low enough temperature, enough wax crystals form to inhibit any mobility in the oil, this phenomena occurs. This is normally around 17.5 °F (8.1 °C) for #2 diesel.

The fuel must be elevated above the gel point temperature to the Ungel point, which is normally near the pour point, in order to become pumpable again. However, most of the waxes will stay solid, and the fuel will need to be warmed up to the Remix temperature to completely remelt and redissolve the waxes.

When a chilly temperature is forecast, anti-gel chemicals are routinely added to diesel or biodiesel. They work by reducing the production of wax crystals in the gasoline, lowering the fuel’s pour point and gel point. Anti-gel additives may or may not have an impact on the cloud point.

What temp does diesel ignite?

Any liquid’s flashpoint is the lowest temperature at which it produces enough vapor to create a flammable combination in the air. If an ignition source is present, the lower the flashpoint temperature, the easier it is to ignite the air. The higher the flashpoint, the safer it is to handle the substance.

The flashpoint of diesel fuel varies depending on the kind of fuel. #2 diesel is the most common type of diesel on the road today. The flashpoint of diesel fuel is between 125 and 180 degrees Fahrenheit, according to a ConocoPhillips Material Safety Data Sheet (52 to 82 degrees Celsius). Any liquid’s flashpoint can shift when the pressure in the air around it shifts.

Can diesel oil freeze?

As the winter months approach, the reduction in temperature puts a strain on diesel engines’ overall efficiency and performance. The risks of extremely cold temperatures can make it difficult for engines to start or even perform properly. Understanding the challenges diesel owners experience during the winter months is the first step in protecting and preventing these dangers.

Water may harm a diesel engine at any time of year, not only in the winter. Water can be introduced to diesel through storage, handling, and condensation in storage tanks. Water in the gasoline, on the other hand, can freeze at 32°F in the winter and clog fuel lines and water separators.

During the cooler winter months, diesel is also susceptible to gelling. As the temperature drops, the paraffin wax in diesel thickens, causing this to happen. As a result, the gasoline becomes cloudy and gel-like, preventing the diesel from burning and clogging filters. If the temperature drops low enough, the fuel can freeze solid and stop flowing, rendering it useless until it re-liquifies.

It’s critical to have a plan in place for winterizing your vehicle whenever the temps drop. The most straightforward solution is to utilize a gasoline additive that can safely remove water from your fuel while also acting as an anti-gel, allowing the fuel to survive cooler temperatures. Fuel Ox Cold Charge, for example, lowers the pour point by 20°F, reducing the effects of wax. It will also safely filter water out of your fuel system while lowering your fuel consumption. If your fuel has already gelled or frozen, Fuel Ox also has an emergency diesel additive called Fuel Ox Heat Bomb that will safely and efficiently thaw and restore gelled or frozen fuel. With Winter on the way, make sure your diesel is protected from the freezing cold! With our Fuel Ox Cold Charge and Fuel Ox Heat Bomb, Fuel Ox can assist you with your Winterization!


Because diesel fuel contains paraffin wax, it gels in cold temperatures, which is an important component that enhances viscosity and lubrication… but this isn’t ideal when the wax thickens as the temperature drops.

The wax in the fuel is an oily liquid state at normal temperatures. However, when the outside temperature drops below the “cloud point,” the paraffin wax solidifies and turns into a hazy mixture, eventually causing diesel fuel to gel.

If left unchecked, the wax may harden into crystals, which will clog fuel filters and lines, preventing fuel from flowing and rendering your engine worthless. This is also characterized as a lack of fuel.


Free water in gasoline will freeze in the cold weather. Ice crystals will act similarly to wax crystals, clogging filters and pipes, causing abrasive wear to fuel systems, and inhibiting fuel flow.

To avoid problems with diesel gelling, its qualities must be modified seasonally to guarantee that it performs well in cold weather.

Jet A-1

Jet A-1 is a kerosine-based fuel that can be used in most turbine-powered aircraft. It has a flash point of 38 degrees Celsius (100 degrees Fahrenheit) and a freeze point of -47 degrees Celsius. Outside of the United States, it is widely available. The UK specification DEF STAN 91-91 (Jet A-1) Nato code F-35 (previously DERD 2494) and the ASTM specification D1655 are the major requirements for Jet A-1 grade (see below) (Jet A-1).

Jet A

Jet A is a kerosine-grade fuel that is generally exclusively accessible in the United States of America. It has the same flash point as Jet A-1, but a lower maximum freeze point (-40°C). It is manufactured in accordance with ASTM D1655 (Jet A) standards.

Jet B

Jet B is a distillate that contains both naphtha and kerosine. It can be used as a substitute for Jet A-1, but because it is more difficult to handle (greater flammability), it is only employed in extreme cold locations where its superior cold weather performance is critical. Jet B has an ASTM specification, but it is delivered in Canada in accordance with the Canadian Specification CAN/CGSB 3.23.


The main jet fuel grade available in Russian and CIS countries is TS-1. It’s a kerosine-like fuel with somewhat higher volatility (minimum flash point of 28C) and lower freeze point (

American Civil Jet Fuels

The ASTM Specification for Aviation Turbine Fuels D 1655 is the most common civil jet fuel specification in the United States, and it specifies the requirements for three types of fuel:-

  • Jet A-1 is a kerosine-based fuel that is identical to Jet A but has a lower freezing point of -47 degrees Celsius.

Jet B is no longer widely accessible, with the exception of portions of northern Canada, where its lower freeze point and higher volatility make it easier to handle and start cold.

UK Jet Fuels

D. Eng RD 2494, issued by the Ministry of Defence, was adopted as the standard UK civil jet fuel despite its origins as a military jet fuel. It has been renamed DEF STAN 91-91 and now specifies the specifications for a kerosine-type fuel (Jet A-1 grade) with a maximum freeze point of -47 degrees Celsius.

Except for a few places where DEF STAN 91-91 is more strict, Jet A-1 as specified by the DEF STAN 91-91 specification is quite similar to Jet A-1 as described by the ASTM D 1655 specification.

Former Soviet Union and East European Jet Fuels

There are a variety of specification grades for Soviet kerosine-type jet fuels, reflecting differing crude sources and processing procedures. T-1 to T-8, TS-1, or RT are the grade designations. A State Standard (GOST) number or a Technical Condition (TU) number is assigned to the grades. In certain cases, the limiting property values, exact fuel composition, and test methodologies differ significantly from their Western counterparts.

Soviet fuels have a low freeze point (equal to roughly -57 degrees C by Western test techniques), but also a low flash point (a minimum of 28 degrees C compared with 38 degrees C for Western fuel). The best quality (a hydrotreated product) is RT fuel (written as PT in Russian alphabet), however it is not extensively produced. Most aircraft manufacturers accept TS-1 (standard grade), which is considered to be on par with Western Jet A-1.

The countries of Eastern Europe have their own national standards and nomenclature. Many are fairly similar to Russian standards, but others reflect the needs of visiting international airlines and have features and test techniques that are similar to Western Jet A-1.

Chinese Jet Fuels

Current Chinese requirements cover five different types of jet fuel. Previously, each grade was designated by the prefix RP; however, they are now referred to as No 1 Jet Fuel, No 2 Jet Fuel, and so on. The kerosines RP-I and RP-2 are similar to the Soviet TS-1. Both of them have a low flash point (minimum 28 degrees C).

RP-1 has a freeze point of -60°C while RP-2 has a freeze point of -50°C. RP-3 is essentially the same as Western Jet A-1, but it’s made for export. RP-4, like Western Jet B and Soviet T-2, is a wide-cut type of fuel. RP-5 is a high-flash-point kerosine similar to that used by naval aircrews on aircraft carriers in the West. RP-3 is now used in almost all Chinese jet fuel production (renamed No 3 Jet Fuel).

International Specifications – AFQRJOS Checklist

A number of fuel suppliers established the Aviation Fuel Quality Requirements for Jointly Operated Systems, or AFQRJOS, Check List as jet fuel supply arrangements got more complex, necessitating co-mingling of product in shared storage facilities. The DEF STAN and ASTM specifications for JET A-1’s most demanding criteria are represented by the Check List. Any product that meets Check List standards will, by definition, also meet DEF STAN or ASTM norms.

The fuel given to the Check List meets the most demanding specifications: –

Eight major aviation fuel suppliers – Agip, BP, ChevronTexaco, ExxonMobil, Kuwait Petroleum, Shell, Statoil, and Total – recognize the Check List as the foundation of their international supply of nearly all civil aviation fuels outside of North America and the former Soviet Union.

Other National Civil Jet Fuel Specifications

There are a plethora of different national specifications. Typically, these are based on specifications from the United States, the United Kingdom, or the former Soviet Union, with minor changes. The modest variations between the ASTM and DEF STAN requirements are increasingly being harmonised. Many national specifications are also undergoing this harmonised process.

What’s the difference between #1 and #2 diesel?

The fundamental difference between Diesel #1 and Diesel #2 is the cetane rating, which, like the octane of gasoline, indicates igniting ease. It’s all about fuel efficiency, volatility, and seasonality, really.

Less wear on your engines’ batteries implies a faster and more efficient start. The increased cetane grade also helps diesel engines run more smoothly by lowering maintenance requirements.

The additional lubricants in Premium Diesel assist keep fuel system parts moving easily. The fuel pump’s and other fuel system components’ lives are extended as a result of the reduced friction.

Fuel systems can become clogged with sediments and other particles over time. While the engine is operating, detergents are injected to Diesel #1 to clean injectors and other fuel system components. Not only does a clean fuel system last longer, but it also enhances fuel efficiency and horsepower production.

Diesel #1 contains lubricants and detergents, as well as other fuel additives that improve engine performance and save downtime. Even in a well-sealed fuel system, air moisture can find its way in and cause major engine problems. Demulsifiers in premium Diesel work to separate emulsified water from the fuel so that it can be filtered out; even in a well-sealed fuel system, air moisture can find its way in and cause major engine problems. Corrosion inhibitors keep rust and corrosion at bay, while stabilizers keep blockages and buildup at bay.

Diesel #1 is sometimes known as winter diesel since it operates better in colder conditions than Diesel #2. It has a lower viscosity and does not gel when exposed to cold temperatures. Most stations sell a premium Diesel blend that is tailored to the local climate.

While premium diesel has a number of advantages, such as fewer maintenance and equipment downtime, regular diesel is less expensive at the pump, which is an essential consideration. However, total cost of ownership should take into account not only the cost savings from the fuel, but also the impact on ongoing maintenance costs. The age and size of your fleet may play a role in deciding between Diesel #1 and Diesel #2.

When deciding between Diesel #1 and Diesel #2 for your fleet, keep in mind that premium Diesel quality differs from station to station. If you choose Diesel #1, make sure your drivers get their fuel at reliable high-volume stations.

Do you want to learn more about the effects of diesel choices on fuel systems? To talk with an equipment professional, contact your nearest Papé Kenworth office now.

Can you use too much diesel extreme?

It’s possible to have too much of a good thing. It’s easy to overdo it with a high-quality diesel fuel additive. Overdosing can result in a slew of new fuel and engine problems, ranging from clogged filters to decreased engine performance and efficiency. Don’t over-treat if you’re losing lubricity.