Diesel electric fuel preheater

8 best preheaters

*Overview of the best according to the editorial board of expertology.ru. About the selection criteria. This material is subjective, it is not an advertisement and does not serve as a guide to purchase. Before you buy it you need to consult with a specialist.

Winter becomes a real test for many cars. If the car is a daily necessity, the owner has to deal with numerous problems associated with low temperatures. A reliable assistant to the motorist in the fight against the cold today have become preheaters. They allow warming up a frozen engine before start-up, saving fuel (no need to warm up the car for a long time), reducing the load on the battery and starter. In the car market there are many different models, which differ in principle of action, degree of autonomy and price. With the help of expert advice the car owner will be able to choose the most suitable device.

How to choose a heater

1. The main criterion when choosing is the energy source . For engine heating, manufacturers offer several popular options.
2. Electricity . The simplest and most effective way to heat fuel and antifreeze are heaters. Unfortunately, the small capacity of the battery will not allow to warm the cooling and heating system of the interior. Therefore, devices working from the on-board network, can only increase the temperature of the fuel (most often diesel). Decent efficiency of warming up the engine before start-up is provided by devices with operating voltage of 220 V. If the car winters in the garage, then such a preheater will be the best option.
3. Car fuel . You can get the necessary energy for heating by burning automotive fuel. There are petrol and diesel versions of preheaters. They are integrated into the cooling system, connected to the fuel line and on-board network. When switching on the device, fuel is fed into the combustion chamber, and the generated heat is used to heat the antifreeze. With the help of a pump, circulation is organized, thanks to which the heat is evenly distributed throughout the engine and the interior. Such heaters are very effective, but the price is high. And the device can often be installed only in specialized service centers.
4. Heat accumulator . With the daily use of the car, you can use a heat accumulator. It is a kind of thermos, in which the warm coolant does not cool down for several days. Stock of warm antifreeze is formed when the car is moving. In the morning, a separate pump starts pumping the liquid from the heat accumulator into the cooling system, warming the engine. In the conditions of the Moscow winter such a thermos is able to retain heat for 3 days.

We have selected 8 best preheaters in the review. All of them are sold on the domestic automotive market. When allocating the places in the rating, the opinion of experts and reviews of Russian motorists were taken into account.

Rating of the best heaters

Best gasoline engine liquid heaters

Gasoline engines are characterized by fast heating, so preheaters are put on cars with a large volume of engines (2.0-4.0 liters). The advantages include autonomous operation and efficiency of heating. The obvious disadvantage is the high price and complicated installation. Experts have chosen several quality models.

WEBASTO THERMO TOP EVO 5 GASOLINE

Preheaters of the German firm WEBASTO are so popular among motorists that the name of the firm has become a nickname. If your car is equipped with a “webasto”, the winter cold is not a problem. Wide range of application finds the WEBASTO THERMO TOP EVO 5 model, designed for installation in gasoline cars. Factory conveyors manufacturers of modern cars integrate this heater in cars, vans, SUVs. The main thing is that the volume of the gasoline unit does not exceed 4 liters. Experts note the versatility of starting. It can be done with a key fob, via a smartphone app or set the start with a timer.

The heater deservedly wins in our rating. Users are pleased with the performance of the device, unpretentiousness and durability.

Heater for diesel. What to choose to overcome the eternal nightmare of “tractor drivers”.

This winter has once again proved that not every winter fuel that is used at gas stations for diesel vehicles can be rightfully called winter fuel. As soon as the thermometer’s column fell to -20°C and lower, the joke came true again, when the operator asked: would you like to put diesel fuel on the filter or pour it into the tank?

But could it be otherwise if, for example, according to the information at the site of Mozyr refinery offering three sorts of winter diesel fuel, when fuelling with diesel fuel of F sort DT-Z-K5 it is impossible to guarantee normal functioning of a diesel engine power system at temperatures below -20°C because of the limiting temperature for filterability of F sort DT-Z-K5?

There is an alternative to grade F. These are diesel fuel of DT-Z-K5 grade 2 with filtration limit temperature not higher than -32°C or DT-A-K5 grade 4 with filtration limit temperature down to -44°C. But let’s not interrogate the reason why not them, but F grade appeared in the tanks of cars that experienced the main problem of diesel operation in winter peak frosts, let’s not. Let’s look for a way to overcome the congenital, or if you want, production defect grade F, because severe cold weather probably came to us not the last time.

The source of the problem is paraffin, which, like water, with decreasing temperature changes its aggregate state, but in contrast to water, which turns into ice at zero degrees, paraffin begins to transform into a solid phase at -5 ° C. Fuel becomes turbid, but as long as the size of paraffin crystals remains smaller than the pore diameter in the filter paper of the fuel filter, there is nothing wrong with the turbidity – fuel will pass through the filter.

However, as the temperature drops further, the paraffin particles grow and aggregate into flakes. Moving with the fuel, they clog the filter, settle on the fuel intake in the tank and in the narrow places of the feeding system, preventing fuel circulation in the engine feeding system, which leads to engine shutdown.

However, the mechanism of diesel fuel paralysis is not a secret for a long time, the ways to avoid it are not new either. For example, adding petrol or kerosene to diesel fuel has been known since the times of the Soviet Union. When the Iron Curtain fell, after foreign cars’ diesels our market began to receive anti-caking additives for diesel fuel.

Kerosene, gasoline and antigels do help lower the temperature threshold of diesel fuel filterability, but each of these ways of fighting for its pumpability through the power system has drawbacks. When kerosene or gasoline is added, the lubricating properties of the fuel deteriorate, which can affect the service life of the rubbing parts of the fuel equipment. In addition, kerosene and gasoline reduce the cetane number, which determines the ability of diesel fuel to ignite itself. This affects the cold start, which worsens in diesel engines with the onset of frost, as well as the increase in engine stiffness, which may affect the durability of the cylinder-piston group components.

One of the disadvantages of antigels is difficulty of their application. The effect is achieved after physical and chemical processes with fuel, which normally take place only at temperatures above +5°C. Even if you do all manipulations with additive at a gas station very quickly, it is not guaranteed that a small amount of it, which should be added to a tank before refueling, has no time to freeze. So, it is better to add antigel in a can with fuel in a warm place, but not all owners of diesel cars can do it in their living conditions.

One more way to prevent diesel fuel freezing is heating. Since paraffin passes from the liquid state to the solid state when cooling, it is necessary to heat the fuel to temperatures at which it melts and remains liquid. But here’s the question: why do owners of cars equipped with a regular filter heater also have a paraffin problem?

The disadvantage of the standard designs is that many of them are liquid and connected to the engine cooling system. It takes some time for the antifreeze circulating through the OEM heater to reach the correct temperature itself after starting the engine. The lower the ambient temperature, the longer this time is. It happens that paraffin has time to clog the fuel filter and fuel intake in the tank before the standard filter preheater and tank heating “return” have time to come to the rescue.

Some additional heaters, which you can buy at retail or service stations, specializing in their installation, are called preheaters for a reason. They are electrical devices, connected to the onboard network of the car, so when the engine is not running, they are powered by the onboard battery, and after starting – by the generator. Depending on the version, the heater can be controlled manually by a pushbutton switch or automatically by a timer switch.

The fuel filter band heater is one of the most attractive in terms of ease of installation, efficiency and price. This heater is put on top of the filter housing and secured with clamps. Hence another advantage of the band device – it provides thermal protection of the filter from overcooling due to blowing by a stream of cold air while the car is moving.

The disadvantage – bandage heaters are only suitable for installation on filters with metal housing. The worse thermal conductivity of plastic affects the heat transfer and heat dissipation from the heater to the fuel, and that is why there is a risk of overheating in the contact zone between the heater and the filter, which can lead to his failure and deformation of the plastic filter housing.

The heater is selected with the height and diameter of the filter in mind. In addition to the size, the price is influenced by the type of control and the voltage in the network 12 or 24 V for which a particular model is designed. The cost of a bandage device with manual control for ordinary cars is 25-30 c.u.

The disk heater is also designed to heat the fuel in the filter. Considering that it is installed only in the filters, which are screwed into the covers, and it has a smaller heating surface area, it is not universal in terms of installation and is not as effective as a preheater as a bandage device. But the disk heater after installation looks aesthetic and due to the fact that its heating element is located directly in the fuel flow, it cope with flow-through heating better than the bandage one, which protects the fuel from freezing while the car is moving. Price – from 45 c.u.

Unfortunately, the disk heater, as well as the bandage one, is not suitable for installation into filters with plastic body. Because of the lower capacity and lower surface temperature compared to band and disk heaters, this disadvantage is eliminated by flexible heaters, which are silicone tapes with sealed electrical leads. Other band pre-heaters lose in efficiency, but their universality is excellent, because besides filters such devices can be passed along or wrapped around the fuel lines, pipes and generally any parts, which heating is desirable, but problematic or even impossible because of the complex shape or size. Ribbon heaters have length from 1 to 4 m, are designed for voltage of 12 or 24 V, cost of such heater of meter length – 35-40 $.

As preheaters can be used also as fuel intake nozzles, but in this case the fuel is heated not in the filter, but in the fuel tank. Such heaters combine the functions of starting and marshalling, that is they provide fuel heating while the car is moving.

There are several varieties of such devices. The most complex have a combined heating: first by power from the onboard network, and then after warming up the engine with hot antifreeze from the cooling system, which comes and goes through the pipes, integrated into the design of the fuel intake. The simpler and more universal ones use only electric heating, they cost from 40 c.u.

In contrast to the flow-through heaters discussed above, flow-through designs are designed only to prevent fuel from freezing during travel. Such heaters are cut into the fuel line, most often directly before the fuel filter, and only work effectively if there is fuel flow in the line.

Again depending on the variety, the heater is controlled either manually or by an electronic unit, which automatically turns the heater on at fuel temperatures below +5°C and shuts it off when that temperature is exceeded. The price of flow heaters – from 60 c.u. and increases with automatic control.

And this is not all the devices that can help the owners of diesel cars to get rid of the threat of freezing fuel. Some of them can be bought at retail outlets, while others will have to be purchased to order. All that remains is to choose the ones that best take into account the design features of a particular car and are most suitable for its operating conditions.

When it is required to drive the car every day and no matter what kind of frost is coming to visit us, the experts recommend to solve the problem in complex, having installed at least two heaters in the most vulnerable places of power system. However, in this approach, we must also take into account the capabilities of on-board power sources, as well as monitor their condition.

Sergey BOYARSKIH Photo by the author and from open sources of ABW.BY