When Does Diesel Start To Gel?

  • 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.

At what temp will diesel gel?

This phrase is self-explanatory, as fuel gelling occurs when the petrol in your tank thickens to the point where it resembles gel. This only happens when the outdoor temperature dips below 32 degrees Fahrenheit, though it’s most likely to happen when the temperature is around 15 degrees or below. This is due to the presence of paraffin wax in diesel fuel. When you need to improve the lubrication and viscosity of the gasoline, that’s a terrific ingredient to have…but it’s not so great when the wax thickens as it gets colder.

As a result, the thicker fuel clogs the filters and eventually stops flowing completely, preventing you from starting your vehicle. So, how can you tell if your car is experiencing fuel gelling? If it’s below freezing outside and your diesel-fueled vehicle won’t start, it’s most likely due to fuel gelling. Fortunately, this common diesel fuel winter issue can be avoided. To be more specific, there are two basic strategies to avoid this problem.

Will diesel gel at 20 degrees?

In diesel fuel, a similar process occurs when the fuel crystallizes during cold weather. Gelling begins to occur when the temperature approaches 10 to 15 degrees Fahrenheit*, which can block the fuel system (*depending on the supply and quality of fuel, gelling can occur as high as 20 degrees Fahrenheit).

How To Tell When Diesel Fuel Begins To Gel

When diesel fuel begins to gel, Berg says there are a few telling indications, the most obvious of which is a loss of power and compression when fuel fails to reach the combustion chamber. If you could see the gasoline, it would have a hazy appearance, indicating that it had already gelled. Other indicators to look for include white smoke coming from the exhaust when trying to accelerate or the engine stopping running when you are sitting idle trying to throttle. Also, if the vehicle starts but does not run continuously, this could indicate that your fuel has gelled. Gelled diesel fuel is almost always the problem, whether it’s a lack of RPMs when an engine is running or a cold winter morning when the truck won’t start at all.

How to Fix Gelled Diesel Fuel?

Many people make the mistake of grabbing a can of ether to start the combustion process when their diesel vehicle won’t start at all. However, there are certain risks with this solution, as there may not be enough fuel to ignite. Spraying too much ether and having ether spray that isn’t contained causes even more issues. The uncontained spray might ignite other hot components, causing engine damage, or too much ether in the fuel line could simply ignite air in the lines rather than gasoline, causing the diesel engine to suffer severe damage. Fortunately, there are alternatives to spraying ether that are far safer. Here are a few preventative measures to consider:

  • Heat is the most effective line of defense. Avoiding frigid conditions by storing your vehicle in a climate-controlled garage or warm area. Other strategies include installing a series of heat-emitting light bulbs under the vehicle, enclosing the vehicle in a tarp with a heater blowing heat, and installing a modern-day block heater on the engine to keep the vehicle sheltered from the freezing temperatures. While building up the electric costs, the utility providers will adore you as well.
  • Kerosene: With the issue of staying warm when it’s 20 degrees below zero, people might experiment with different fuel mixtures. Pouring kerosene into the fuel tank to lower the freezing point is the most typical method. To take advantage of kerosene’s lower freezing point, many people mix #1 diesel, which is a combination of kerosene and #2 diesel fuel. This mix is frequently accessible in the northern parts of the country, but in the southern parts of the country, where temperatures are normally warmer, the #1 diesel may not be available. In either instance, kerosene has drawbacks, the most notable of which being reduced fuel mileage and efficiency. If, on the other hand, the truck stops running and kerosene is chosen, it is strongly recommended to leave the engine run long enough to combine the fuels and provide a continuous flow of the mixture. Consider the time it takes for the kerosene to defrost the tank in a semi-truck when operating with hundreds of gallons of fuel in a tank. The kerosene must next melt the frozen fuel lines and clogged fuel filter. The entire line from the gasoline tank to the filter to the injectors may take an hour of idle time to defrost.
  • Fuel Additives: There are now fuel additives that can provide a simple, low-cost, and no-hassle method to prevent gelling that any car owner can do themselves. “When considering an addition, Berg advises, “do your homework and analyze all of the products and promises.” “Investing a bit more time and effort to discover the greatest product is occasionally worthwhile. Additives are a means to offer an extra layer of protection to prevent the wax in diesel fuel from becoming thick, similar to wearing layers of clothing in the cold.” Many products contain alcohol, according to Berg, so look for one that provides not just proper temperature coverage but also protection for the entire system, including lubricity, cetane, water dispersion, and a success guarantee. Many preventive options are available, including some top picks being Diesel Winter Anti-Gel, which promotes coverage down to -40°F.

How to Prevent Diesel Fuel Gelling?

So, what’s the big deal about taking the effort to prevent diesel fuel from gelling? “If you contact a tow truck, you may still be stuck with a vehicle that won’t start after paying the tow cost,” Berg explains. You can save yourself the $80 and the headache in the case of a personal or light-duty car, or the $500 tow bill and missed time on the interstate in the case of a truck. Instead, taking use of the finest scientific additives could safeguard you from getting stuck in the cold for only a few dollars in preventative and an easy pour into the tank.

Emergency additions are also available for people who have failed to heed the warning, there has been no prevention, and gelling is still a possibility, or has already occurred! Diesel Winter Rescue, for example, is a formulated substance that requries gelled fuel and de-ices frozen fuel filters to restore diesel fuel flow to the engine, allowing the vehicle to resume normal operation. Diesel Winter Rescue, for example, is a good alternative to keep in your vehicle during the winter months just in case.

At what temperature does untreated diesel gel?

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.

Can diesel gel while driving?

Modern diesel engines do not return as much fuel to the tank as older diesel engines did, therefore the fuel does not stay warm while the engine is running. While driving, the fuel tanks can literally gel. When the temperature of diesel fuel drops, the paraffin that is normally contained in it begins to harden.

Can you put too much anti-gel in diesel?

Is it possible to use too much anti-gel in diesel? You’ve probably added much too much high-quality diesel fuel additive. Overloading your engine can result in clogged filters, reduced engine performance, and potentially a whole new set of fuel and engine issues. If you’re losing your libido, don’t overdo it.

Will diesel Ungel on its own?

A variety of things can be put to a gelled tank to aid in the recovery of the fuel to its original state. Opti-Lube Gel Melt and Diesel 911, for example, are made specifically for gelled fuel. Simply fill the tank with one of these and follow the dosing directions. There’s no need to heat or mix the tank. These can take a long time to install, depending on the size and shape of the tank. The treated fuel in the tank may not be able to reach gelled fuel that is not in the tank, such as in fuel lines and filters, which is a significant constraint.

How cold is too cold for a diesel engine?

When it comes to diesel trucks, how cold is too cold? At 15 degrees Fahrenheit (-9.5 degrees Celsius), the diesel fuel in your fuel tank will gel and you will have problems starting your engine. Your diesel vehicle will have troubles if the temperature drops below 15 degrees Fahrenheit / -9.5 degrees Celsius. The diesel won’t be frozen solid, but it won’t be liquid either. You must now rely on heating solutions such as block heaters and glow plugs, which are not available on all diesel engines.

There’s a lot of debate regarding what temperature is too cold for a diesel truck. On the internet, it is stated that the freezing point of diesel fuel is roughly -112 degrees Fahrenheit or -80 degrees Celsius. Now you believe you will never be in a region that gets that cold, so you should be fine. Wrong.

It is not necessary for the diesel in your fuel tank and fuel lines to be solidly frozen to cause you problems. When the temperature drops below 15 degrees Fahrenheit / – 9.5 degrees Celsius, the diesel fuel begins to change shape and becomes more like a gel. Consider a gel-like fuel that travels from the fuel tank to the engine. Traveling through the fuel lines would be difficult, and you would have difficulty starting your engine in the frigid winter.

Product Details

In cold temperatures, use to liquefy frozen or gelled diesel gasoline caused by wax production or ice crystals. Quick-Thaw will completely thaw the whole fuel system in roughly 20 minutes if applied according to the guidelines. Excellent for diesel cars operating in colder locations, where wax crystals found in low- and ultra-low sulfur diesel fuels can cause filter blockage.

A bottle of Quick-Thaw should be kept on hand in every diesel truck for emergency cold weather rescue treatment.

Can gelled diesel damage injectors?

The gelling, on the other hand, might not be enough to damage an injector. In other words, it gelled, and you didn’t try to run it again until it ungelled. However, if the fuel leading to the injectors has gelled up and the FICM is driving them, the injectors will be starving for fuel. It’s the same as if you were in a low (or no) pressure situation.