Car owners are increasingly switching their cars to gas. This is due to the fact that the usual gasoline is becoming more and more expensive. Gas, on average, is about 30-40% cheaper than gasoline. Depending on the operating conditions and the volume of fuel consumed, the installation of gas equipment pays for itself in a period of 6 months to several years. However, in addition to installing a cylinder, gearbox, lines, injectors and other equipment in the car, you need to prepare the engine itself for the new fuel, first of all, choose the right spark plugs for gas in a car with LPG.
It would seem that such a simple component of the ignition system should not have much impact on operation or create problems. On the contrary, choosing the right spark plugs for LPG is very important, both for fuel economy and for overall ride quality. First, we will talk about which spark plugs are best for 4th generation LPG, and then we will explain their differences from conventional ones.
IN THE TEAM - REPLACEMENT
Of course, you need to change the spark plugs. If only because all our previous publications (ZR, 2005, No. 10; 2007, No. 8; 2008, No. 9) invariably revealed a difference in the behavior of gasoline engines after replacing any of the “ignition” elements - from spark plugs to wires. And then - a change in fuel: the gas burns differently, and the mixture is leaner. The combustion rate is lower, the temperatures are higher - but it burns cleaner, therefore, there are fewer deposits. But these are precisely the parameters that influence the choice of at least the glow number of candles! So is it possible to use regular spark plugs there, as for a gasoline engine? And are there any special “gas” ones in nature?
Spark plugs for gas engines: what to consider when choosing
Let's start with the fact that recently, against the backdrop of constantly rising prices for gasoline and diesel fuel, the installation of gas equipment on a car with a gasoline engine has become a truly widespread phenomenon. This option allows you to get the maximum benefit, since switching a gasoline car to cheaper gas makes it possible to significantly reduce fuel costs.
It should also be added that diesel models, even taking into account their high efficiency, are more expensive than gasoline ones, and are also not without a number of their own problems. As for electric cars, such cars are still in the minority. It turns out that in fact the only available alternative is the ability to convert the car to run on gas.
At the same time, not all motorists, after installing LPG, take into account a number of features and nuances that arise after changing the type of fuel. In other words, in order for the engine to operate normally on gas, and also to avoid a reduction in the life of the internal combustion engine, it is necessary not only to correctly install and configure the gas system, but also to replace some elements and working fluids. More precisely, we are talking about motor oil for gas engines, as well as spark plugs. If everything is more or less clear with engine oil, then difficulties may arise with candles. Next we will talk about why to change spark plugs for gas equipment, as well as what needs to be taken into account and how to choose the right spark plugs for a gas engine.
VERY COMPLEX QUESTION
This is exactly how the Internet responds to the first attempts to find spark plugs for equally effective ignition of gas and gasoline. However, five participants were still identified. Germany is represented by a set of platinum spark plugs Bosch Platinum WR7DP, the Czech Republic - Brisk LPG LR15YS Silver. The honor of Japan in the competition will be defended by two sets of different companies - iridium NGK LPG LaserLine No. 2 and Denso IW20. The Ukrainian Plazmofor Super GAZ represents the Slavic brothers. The selection criterion is a win-win: all these kits are recommended for use on gas engines by the manufacturers themselves on their websites. And as a “zero meridian” for reference, let’s take the obviously good BERU 14R-7DU spark plugs from France, which, however, are focused only on gasoline and are not provided with a clear recommendation for use on “blue” fuel.
Tips and tricks
As you can see, choosing the right spark plugs for gas engines is not the easiest task. Moreover, quite often you can come across the statement that gas spark plugs are a complete analogue of gasoline spark plugs, that is, there is no need to use such solutions. If we add to this the extremely high cost of top-line gas equipment products, then it is clear why there are many supporters of this opinion among motorists.
We also recommend reading the article about how often you need to change the spark plugs in your car. From this article you will learn about the average service life of spark plugs, as well as what affects this indicator and when it is optimal to change spark plugs, taking into account certain factors, conditions and features.
In other words, drivers often tend to think that cheap gas spark plugs are worse than average gasoline plugs, while it is no longer advisable to use expensive gas spark plugs. Let's be somewhat clear.
Indeed, if you compare expensive positions for gasoline and gas, in practice the driver will not feel any noticeable difference. From this we can conclude that, for example, the use of conventional iridium or platinum spark plugs with HBO does not mean that these spark plugs clearly work worse or last much less.
At the same time, the cost of such products is almost on the same level as similar gas ones. It is quite logical that the owner of a car with LPG should not immediately change existing iridium or platinum spark plugs. You can switch to gas options after the end of the service life of the spark plugs, taking into account some differences and adaptation to gas fuel.
If the car has regular gasoline spark plugs, and average or cheap ones, then even mid-level gas plugs will actually be better. Let us remind you once again that gas spark plugs have a narrower gap between the electrodes, which makes it possible to ignite the gas-air mixture no less efficiently than conventional spark plugs with a gasoline-air mixture.
Also, spark plugs for gas motors have increased resistance to heat, heat index number, etc. This means that they are able to operate in higher temperatures and cope with the thermal load that increases after switching to gas.
SPARK PLUGS FOR GAS AND GASOLINE: COMPETITION PROGRAM
We adjusted the tests to the dual-fuel principle - gas/gasoline. First, we ran our usual program, tested in previous spark plug tests, on a VAZ-21083 engine in a regular gasoline version. And then they repeated it on the same engine, having previously equipped it with Italian gas equipment. The principle is common: in the same modes - from minimum idle speed to heavy loads - power, fuel consumption, and toxicity were measured with each set of spark plugs. In addition, the temperature of the exhaust gases was measured: the main horror story of gas opponents is engine overheating!
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Temperature models of BERU 14R-7DU (left) and Denso IW20 (right) spark plugs at a crankshaft speed of 2000 rpm (external speed characteristic, VAZ-21083 engine).
This is how the temperature in the engine exhaust pipe increases when switching to gas. Temperature models of BERU 14R-7DU (left) and Denso IW20 (right) spark plugs at a crankshaft speed of 2000 rpm (external speed characteristic, VAZ-21083 engine). This is how the temperature in the engine exhaust pipe increases when switching to gas.
On gas, the advantages of these spark plugs were even more pronounced. There is a more noticeable increase in power - up to 6%, and fuel economy - up to 7.5%. But the most interesting thing happened with toxicity. A significant improvement in combustion quality, which resulted in a decrease in CO and CH, was compensated by an increase in the content of nitrogen oxides NOx. Everything is clear: the intensity, and with it the combustion temperature, increases, and the yield of this rubbish increases. And the emergency cycle only made the picture worse.
Rating categories
Even an experienced technician will not give you a definite answer to the question of which spark plugs are best used in gas equipment.
Many drivers boldly reach for universal products that do an excellent job with the tasks assigned to them.
The range of specialized spark plugs is practically not expanding. Therefore, the leaders of recent years remain in their established positions.
The only question is how much money are you willing to spend on the best spark plugs for a gas engine. Everyone has their own financial capabilities. Spending huge amounts of money on the most expensive goods is far from rational and correct. But it’s also not worth taking the cheapest options if we are talking about a fairly expensive car.
To simplify the task of choosing, the rating of the best products is divided into 3 price categories:
- budget;
- Average;
- expensive.
Having studied the presented options, each car owner can decide for himself which spark plugs for LPG are better in his opinion and what he is willing to spend his money on.
Budget category
Don't expect special features and functionality from the cheapest products. This is not the category where you can find the best spark plugs for propane ignition. But here, if you are interested in which models are suitable for a limited budget, you can present several options.
- Plasma for super gas. This product is made in Ukraine, which has only a low cost in its arsenal of advantages. If you compare them to mid-range and high-end candles, they are not even close to each other. One set of these devices will cost no more than 500 rubles. At the same time, the product life is about 100 thousand kilometers.
- Beru 14R7DU. Another option for a budget spark plug. But here we are already talking about a French manufacturer. The kit already costs 1,200 rubles with a service life of about 150 thousand kilometers. When switching to LPG with such spark plugs, one should take into account the reduction in power and increased consumption of blue fuel. But the decrease and increase are within normal limits. It is only important that the plugins perform their functions.
- Plasmophore Classic. A good option for domestically produced forks, it cannot boast of excellent characteristics. Report average results for performance and lifespan. For budget cars this is a good choice.
- Spark Gas Super. Another domestic product presented in the budget price segment. The service life of such spark plugs is up to 150,000 km. Although reviews say that the real service life is about 100-120 thousand. km. This largely depends on the operating conditions and the LPG itself, the condition of the car and driving style.
- Cheerful Silver Forte. Their development is presented in a more expensive segment. But these are the candles that are considered budget. Brisk has a good reputation, although they are considered cheap products, but do not have exceptional properties. A good option for your money.
- A fast line in the shape of the letter A. Again a representative of the Brisk company, which, albeit with difficulty, entered the budget segment. For a set of 4 pieces you will have to pay at least 500 rubles. But the price is fair.
All the gas spark plugs presented are not the best. But if we consider the purely budget segment, then they are worth taking a closer look at.
Experienced drivers who install gas equipment even in inexpensive cars admit that it is better to take good quality spark plugs from the very beginning. They will last longer, burn the mixture more efficiently, and help you save money on spark plug replacements.
Therefore, the budget spark plug category should only be considered if you are on a very tight budget or when there is an urgent need to replace parts without being able to buy a higher quality version.
Middle category
It is much wiser and more correct to pay attention to the best spark plugs designed for gas equipment or gas appliances belonging to the middle price segment. This is an excellent compromise between quality and cost.
The middle category has its leaders and favorites, who have held first place for years. This is largely due to the fact that they simply do not have worthy competitors. Few companies produce separate or specialized spark plugs specifically designed for LPG equipment. We are mainly talking about universal devices.
But even among good models there are good options that are relatively inexpensive, and their characteristics are far ahead of the budget category.
- WR7DP from Bosch. One of the most popular gas equipment among car owners. These products have a somewhat unusual design, since the electrode is almost completely installed in the insulator, which provides a high level of protection against soot and the accumulation of all kinds of deposits. The increase in gas combustion efficiency is insignificant and amounts to about 4%. Consumers also note rather low-power characteristics, which brings Bosch’s developments a little closer to budget solutions. But the price here is also right. The kit costs about 1,500 rubles.
- Brisk and their mid-priced LR15YS spark plug. A worthy choice for people looking for inexpensive but high-quality specialized devices suitable for igniting a gas-air mixture. No major changes in blue gas flow are expected after installation of these plugs. The difference is about 2%. But the products are very inexpensive. You will have to pay about 750 rubles for the set.
For almost anyone looking for the best value for money, it makes sense to choose this category of automotive spark plugs designed specifically for gas appliances.
But sometimes drivers are willing to spend even more. In this situation, it’s worth looking for the premium segment now.
Premium category
If you want the best plugins you want to use for HBO Generation 4, but want maximum performance, performance, and durability, you'll have to pay a hefty amount of money for the bundle.
In the premium segment, i.e. Among the most expensive spark plugs for gas equipment, it is worth highlighting some of the most attractive spark plugs in terms of characteristics and properties:
- IW 20 made by Denso. This is a Japanese manufacturer that produces the highest quality parts. A set of these goods will cost at least 3 thousand rubles. When ordering online you usually need to spend $50-60. The installation allows increasing the efficiency and power of the power unit by 5%. And for the blue one, fuel consumption immediately drops by 7%, which is a very important indicator. Especially when compared with representatives of other price categories. Here it is important to properly configure the engine and gas system from the very beginning in order to get all the benefits of buying expensive spark plugs. Otherwise the costs will not be justified.
- Laser line 2 from NGK. One of the best HBO spark plugs available in the domestic market. During tests, they clearly proved that they are not inferior to Denso's competitors, and in some cases even inferior to them. But the costs are higher. The price of the kit starts at $80. This can be explained by the high quality of the products, as well as the use of iridium and platinum in production. Such plugs have a service life of at least 150 thousand. km. But there are clear examples of how Laser Line 2 stood at 200 thousand kilometers.
- NGK 1511 / LPG4. The iridium spark plug is intended for use in cars with a gas installation. Suitable for a wide range of models. The diameter of the thread used is 14 mm. This is a single-electrode part made of solid metal, which gives a good increase in power and reduces fuel consumption. But be prepared to pay at least 1,500 rubles for one piece.
- NGK 1640 / LPG7. Here the caliber number is 7, and the thread diameter is standard - 14 millimeters. Made from iridium. Costs about 1600 rubles per piece.
- NGK 1565 / LPG6. Another excellent 6 gauge iridium spark plug. This is a single electrode, single metal product with the same diameter filament as the previous version. The price is also very close. For one candle, the car owner will have to pay about 1,500 rubles.
The category of premium spark plugs has objective advantages over cheaper products compared to spark plugs adapted for gas appliances.
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Why? Because the combustion rate of gas fuel is much lower than that of gasoline. And the more sluggish the combustion in the cylinders, the more important is the intensity of ignition of the gas-air mixture. That’s why platinum and iridium spark plugs, with their thin electrodes and inherent high discharge intensity, accelerate the flame front in the cylinders much more efficiently than conventional ones.
How to check and how to set it
The process is not as complicated as it seems at first glance. To begin with, we simply unscrew the spark plugs, then look for damage; if there is none, then you can first clean it, then check the gap.
Of course, the gap can be measured with conventional measuring instruments, just a ruler. However, it is very difficult to determine 0.5 or 0.7 mm by sight! Therefore, now in stores you can buy so-called sets of “feelers” or special keys for checking the gap.
The probes are similar to metal curved letters “G”, with different sizes; we simply place them between the electrodes and determine the gap with an accuracy of 97%. If it is larger, for example on an injector than 1.1 mm, then the contacts are brought closer to each other, you can simply tap with the handle of a screwdriver. If it’s too close, then we move them apart from each other, again checking with a probe.
Watch my video about the gap.
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Overlapping temperature graphs for the same set of spark plugs when running on gas and gasoline shows that gas fuel adds up to 60 degrees to an already hot pipe. And candles are very sensitive to temperature! Too low degrees are contraindicated for them: they begin to become overgrown with deposits - products of incomplete combustion of fuel and oil. High temperatures burn off these deposits, but can lead to glow ignition of the fuel. We remind you: this is when combustion begins not from a spark, but from contact with a hot part. And the hottest part in the cylinder is the spark plug insulator.
Installation of candles
To install spark plugs for 4th generation HBO or any other, you need a spark plug wrench; in some engine designs it is possible to do this using an open-end or socket wrench. To do this, you need to remove the caps with high-voltage wires and unscrew the old ones, counterclockwise.
If you screw the new spark plugs into the cylinder head poorly, they will heat up more, the consequences of this are described above. If you overtighten, you damage the ceramic insulator, it may and will work, but you can’t expect stable operation.
Important: For proper tightening, follow the advice: tighten them by hand, then turn them a quarter turn with a wrench. If you are re-installing spark plugs - a third of a turn, and if the sealing surface is conical - by 15%.
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This is where the advantages of spark plugs with thin iridium electrodes appear once again. It is difficult to measure their temperatures - computational modeling methods have been invented for this case. So, the temperature of the central electrode of an iridium spark plug with a thin electrode is 60–80 degrees lower than for a conventional spark plug. Why? The heating area of a thin electrode is much smaller, and the thermal conductivity of an iridium alloy is much higher than that of a steel conventional electrode. Let us add that the heat resistance of platinum group metals is also higher.
WHAT IF YOU DON ' T CHANGE?
But what will happen if you leave ordinary candles when switching to gas? It's okay! This is evidenced by a comparison of ordinary BERU spark plugs and Ukrainian Plazmofor spark plugs specially “tailored” for gas fuel. But the resource of a regular spark plug using “blue” fuel will obviously be lower. However, a simple candle is obviously cheaper than an exotic iridium-platinum...
Our summary: for working on gas fuel, it is better to choose thin-electrode spark plugs recommended by the manufacturer.
Spark plugs, or Gas lighters
Why special candles for HBO?
Before discussing which spark plugs are best for gas, depending on the financial capabilities of the consumer, it is necessary to consider an equally important controversy.
Experts who install gas appliances on cars originally equipped with gasoline power units recommend replacing traditional spark plugs with special ones designed specifically for working with blue fuel.
But many drivers and tram drivers do not understand why they need to replace existing spark plugs with some special ones, supposedly intended exclusively for gas ignition. They are sure that this is just a clever marketing ploy, and there is no real difference between the devices.
It should be noted that traditional spark plugs are designed to operate by burning a fuel-air mixture, that is, a combination of fuel vapor and oxygen (air). And when they switch to air and gas, they can lose their performance quite quickly and eventually fail.
We should not forget about the higher electrical resistance of the gas-air mixture compared to the air-fuel mixture. For this reason, it is essential that the gap between the spark plug electrodes be smaller to ensure efficient and precise ignition.
After narrowing the gap, manufacturers did not stop there. Today you can hear from manufacturers of glow plugs for gas equipment that only specialized high-quality products containing only precious metals can operate on gas. This is the most expensive and affects the cost of the device.
It is much more correct to explain the need for special candles, since when burning gas the temperature is much higher than when burning traditional fuel. High temperatures accelerate wear and therefore shorten the life of the spark source.
All this indicates a real need for the use of high-quality products made from specific materials.
Modern and efficient SBO spark plugs are made from 3 materials:
- The side electrode rods are made from copper. This is because copper can improve heat dissipation performance.
- Platinum. It is used to form solder on the side electrodes.
- Iridium is also widely used. It is needed as a material for creating central electrodes.
This is the general principle of forming a spark plug for gas appliances. Each manufacturer can make their own adjustments, experiment with the design and apply additional protective layers to the surface of the body. All this is done to reduce the activity of carbon monoxide formation from exhaust gases, increasing efficiency and extending the life of the product.
But all this looks ideal only on paper or in theory. In practice and in real life, it is difficult to find spark plugs specifically designed for LPG applications.
Considering the constancy of favorites, you can determine which spark plugs will be most suitable for gas appliances at the moment and why you should choose certain options.
