ALEX LPG / FAQ – frequently asked questions about autogas


All you need to know about the LPG

Anyone who is interested in gas systems for cars has questions that need to be answered. We can talk about it all the time - this is what ALEX's years of experience and passion mean.

Our experts have answered the most popular questions, such as: is it profitable to install the LPG system, how quickly will the gas system pay for itself, how much does an LPG kit cost, will your car lose some of its power after the installation of the system? These and other useful information can be found below. Remember – if you cannot find the answer to your question here, feel free to contact us. We will provide you with information, explanation and help.

  • What do you need to know about the LPG system for cars?

    In the Polish market, gas systems have been known and popular since the beginning of the 1990s. The technology has advanced since then, and problems that used to be associated with autogas no longer exist. However, people still commonly believe in these myths and legends. As a result, drivers still have many doubts. They should be dispelled before you decide to install a gas system in your car.

    First and foremost, you should bear in mind that gas-powered cars are cost-effective. LPG is nearly half the price of petrol or diesel. Thanks to that, the money you invest in the installation of the system will be more than compensated. Moreover, with your tank full of gas or other fuel you can cover a really long distance without additional refuelling. These facts may convince you to install LPG. Information about details is available everywhere on our website. You can also contact our onsultants directly.

  • Is autogas environmentally friendly?

    LPG is the cleanest fossil fuel. Autogas exhaust contains from 10 to 15% less carbon dioxide, 20% less carbon monoxide, from 55 to 60% less hydrocarbons than burned petrol or diesel. The carbon footprint of LPG is 20% lower than that of fuel oil and 50% lower compared to carbon. Gas does not contain benzene, lead compounds and sulfates. Choosing LPG as the fuel for your car means that you care for your health and the environment.

  • Is it worth installing the LPG/CNG system even when I cover low mileages?

    The investment in autogas is economically viable, even in the case of low monthly mileages (less than 1,500 km). Therefore, there is only one answer: yes, it is worth installing the LPG/CNG system in your car. Sooner or later, depending on the number of miles driven, the investment will pay for itself. It’s just a matter of time. We have developed a very helpful calculator that uses the average petrol consumption and average monthly mileages to calculate how soon the cost of LPG installation will be compensated in your case.

  • How much gas does a petrol engine burn?

    Usually, a car will use from 15 to 20% more gas than petrol. It stems from the difference in fuel mass relative to their volume. An optimally calibrated OPTIMA system burns on average only 10-15% more LPG than petrol. It doesn’t change the fact that the savings from the use of autogas amount to even 50% during each refuelling. Comparing the energy value of fuels according to their weight, you will find out that a kilogram of propane-butane is more energy-efficient than a kilogram of petrol (unfortunately, we refuel our cars in litres, not kilograms – hence the differences).

  • Is it necessary to check the condition of the engine before installing a gas system in my car?

    Before converting your car to LPG you must check whether the engine is fully operational. Make sure that your car is in perfect technical condition. Take look at both the engine (the head, valves, pistons) and its accessories (the carburettor, the ignition, plugs and so on).

    If you have been putting off any repairs, have them done before your visit to the gas workshop. Although there may be some additional costs associated with the preparation of your car, remember that the installation of an LPG system is an interference with the original layout of your car. It is worth making sure that the “patient” is completely healthy before the procedure. You perform maintenance of your car on a regular basis? Excellent. Your car is ready for LPG.

  • Where to find the engine code?

    Often, when asking for the price of assembly of an LPG installation, the installers ask for the engine code. Depending on the car make, the engine code may be located in different places. In this post, we explain where to find the engine code.

  • What should I remember about when using a car powered by gas?

    To ensure that an engine that has been converted to gas will operate properly, you must maintain the high and low voltage electrical system in a proper condition. Apart from that – once a year or each time you have driven 10,000 km – your LPG system should undergo a check-up including computer diagnostics and replacement of liquid and gaseous phase filters. It is also worth conducting more frequent inspections of the ignition system (inspection of plugs and high-voltage wires) as well as inspections of valve lashes (approx. every 50,000 km).

  • Does the LPG system damage the engine?

    An LPG system that has been properly selected and installed in a car that is in good technical condition does not damage the engine, just like an operational electrical system does not cause a fire in the house. Moreover, LPG fuel has a higher octane number (100 – 110) than petrol (95), which reduces the risk of knocking combustion.

    Situations in which the system may exert a negative impact on other components are mainly caused by systems that weren’t installed at a specialist workshop, or were assembled using components from various sources. It is not worth trying to save money in this case – although prices offered by people who do not specialize in the installation of gas systems may be tempting, using their services will backfire in the future as you will be forced to frequently conduct costly repairs. Therefore, it is best to choose the services of a professional workshop that specializes in LPG/CNG systems.

  • Does it matter at which workshop I will install the system?

    It is of key importance. Only experienced specialists will properly install and configure the system. Only the combination of the best quality of products and professional work of installers will provide you with actual savings and satisfaction from the use of autogas. It is worth remembering that problems with LPG-powered cars are mainly caused by mistakes made by installers. Therefore, when looking for a workshop, consider only the ones which hold certifications (manufacturer’s approvals) and show exemplary installation practice.

  • Who provides the installation documents needed to make an entry in the registration certificate?

    All documents, i.e. an excerpt from the approval, the invoice, the gas tank certificate as well as the warranty and the inspection book, should be provided by the installer. That’s why you should use the services of a recommended workshop. For example: all installation workshops that cooperate with ALEX are licensed to install systems from at least one manufacturer (i.e. valid ITS registration) This ensures that at such a workshop you will receive all documents needed to make an entry in the registration certificate.

  • What documents do I need, and how much time do I have after the installation to register the installation?

    To register the LPG system at the Department of Motor Vehicles you need to bring the invoice for the installation of the system (containing VIN and the registration number of the vehicle), an excerpt from the certificate of approval of the installation method, the registration certificate and the vehicle card (if issued). You have 30 days to enter the installation of LPG in your registration certificate.

  • How long is the warranty for the LPG System?

    The ALEX IDEA and ALEX OPTIMA controllers we produce are covered by a 5-year manufacturer’s warranty. Other components of the LPG system and assembly are covered by a 2-year warranty.

  • Is it possible to install a used gas system in my car?

    It is not possible and prohibited by law. In 2005, the Sejm decided to prohibit reinstallation of second-hand gas system components.

  • The 10-year validation period for an LPG tank is coming to an end. What do I do?

    If the period for which an LPG tank has been approved for use is coming to an end, you must go to a specialist workshop which will conduct an internal revision and a hydraulic pressure test. If the obtained result is positive, you will receive a test protocol as well as an administrative decision concerning further use. Remember that some tanks cannot be validated again. In such case, you will have to replace the tank with a new one.

  • I cannot find the certificate for the LPG tank, and I cannot have the technical inspection done without it. Can a duplicate be issued?

    The technical test of the tank is valid for 10 years from the date of manufacture. You can only receive a duplicate before the validity period expires. To order a duplicate, you must first check the following data on the rating plate (provided on each tank): the name of the manufacturer, the number of the manufacturer, tank dimensions (its capacity and diameter), production date/validity date of the technical test, approval number (67R-) as well as the Approval of the Transport Technical Supervision (the TDT mark). A duplicate can be ordered directly at the Office of Transport of Technical Inspection – [INSTRUCTION].

  • Does LPG lower the power of the engine and affect its performance?

    Indeed, back when cars were equipped with carburettors (of the 1st generation), or archaic systems of the 2nd, a decrease in power did occur. However, it’s long in the past now. The currently applied solution – sequential gas injection – ensures virtually the same driving dynamics and parameters as in petrol-fuelled vehicles. Theoretically, there can be a decrease in power of up to 3% after the installation of the LPG system. In reality, however, the driver does not feel any loss of power or acceleration.

  • How quickly does the car switch from petrol to gas?

    A lot depends on the ambient temperature, engine properties as well as how quickly the coolant heats up. The engine always runs on petrol after being started. It will switch to gas after reaching an appropriate temperature (approx. 30°C) of the coolant, which is used to heat the reducer (which changes the state of gas, from liquid to volatile). It usually happens after driving several hundred meters. It is different after stopping and restarting the heated engine. In such case, the engine will immediately switch to LPG.

  • I am afraid that I will be feeling a jolt during the switch to LPG. Is it true?

    No. If the autogas system was properly installed and adjusted, the switch between fuels will take place automatically and will not be felt by the driver or passengers.

  • Is the LPG system 100% safe?

    Although gas is a highly-flammable substance, gas systems are among the safest systems in cars. Why? Restrictive standards and technology require greater protection than in the case of petrol systems in standard cars. Tanks can endure much more than typical situations on the road. Common myths and stereotypes have been debunked many times – LPG systems really are very safe – both in theory and practice. You should remember to choose approved, high-quality products and use the services of professional workshops specializing in the installation of LPG systems.

  • Do tanks explode?

    LBG cylinders do not explode. It’s one of the myths related to automotive gas systems. Gas tanks are designed in such a way that it is not possible for them to be ruptured. They are made of very thick metal sheets and have additionally reinforced bottoms as well as a number of valves that guarantee the safety of the entire system. Cases of cars exploding or burning down, which are sometimes widely reported in the media, are caused by defects in the petrol system, not in the gas system.

  • Is it difficult to operate an LPG-powered car?

    It’s very simple, and practically boils down to… filling your car up with autogas. From the perspective of the driver, a properly installed and adjusted LPG system is maintenance-free. There is only one additional switch on the dashboard. It informs the driver which fuel the car is currently running on and how much gas there is in the tank. Today’s systems are controlled by electronics. They are responsible for the moment of switching the power to autogas and all other parameters of engine operation.

  • How does LPG impact the engine?

    LPG is a fuel that is fed into cylinders in gaseous state. It is the best option for the engine, which directly translates into longer engine life. It makes ignition smoother and more efficient and prevents the protective layer of engine oil from being washed off the cylinder walls. LPG does not cause corrosion of metal parts of the engine, does not form carbon deposits and metallic sediments. It has engine-cleaning properties. After the installation of the gas systems, previously accumulated contaminations may be even removed from the system.

  • Is it true that some engines are better and others are worse suited for the installation of a gas system?

    Successful conversion of cars to LPG isn’t determined by the engine, but the LPG components, the technical condition of your car as well as the knowledge and experience of your installer. All cars with spark ignition can be converted to run on gas. However, the mixture of propane butane requires better combustion conditions than petrol. Therefore, the condition of the ignition system is one of the elements that are important for the proper installation of the gas system.

    Sometimes, the installation of the gas system and driving on gas may reveal previous negligence in terms of maintenance. Therefore, the system should be installed at a good, recommended workshop. A workshop that will thoroughly check the technical condition of the car and adjust LPG components to its capabilities and the expectations of the customer before accepting it for installation.

  • Is it a good idea to install LPG in a hybrid?

    Hybrid vehicles run on electricity only at low speeds, for example while driving around the city. At higher speeds, however, or on motorways, the car will pretty much use only the internal combustion drive. This is where the LPG system comes into play.

    Hybrids powered by LPG have a lot of potential. It is a cost-effective and good technological solution that brings real benefits not only to the user, but also to the environment. The use of the car is just as simple as before the installation. The installation of the gas system will make a hybrid really economical. The cost of refuelling is reduced by half, and the car becomes even cheaper in use in the city, and much more economical on the road. The only thing that can be cheaper is a scooter 🙂

  • Is it safe to install LPG in direct injection engines?

    Nowadays, LPG systems are commonly installed in cars with direct injection engines, and correct installation ensures proper engine operation. All the “direct injection is not suitable for LPG” discussions that can be found on the Internet stem from poorly selected components and clumsy attempts at installation. Therefore, if you care about quality and good service, visit our recommended, experienced installation workshops.

  • Does LPG have an unpleasant smell?

    LPG is odourless. The unpleasant odour is due to the chemicals added. They are added intentionally – for the safety of drivers and passengers. If you begin to smell gas in your car, consider it a warning sign. Something is probably going on with the system, and you must go to a service centre to check your vehicle for leakages. Gas cannot escape from a properly installed and maintained system, so you should not be able to smell it.

  • New engines are said to not tolerate autogas?

    It is not true. Due to cost saving by manufacturers and the resulting lower durability of materials in new engines, installers must work harder on the tuning and installation in such cars as well as selecting LPG system components. It all depends on the installer’s knowledge. For example, many new vehicles are equipped with a fuel pressure sensor. When the installed gas system lacks additional, suitable electronics, a fuel pressure error will be reported. In this case, we must install a fuel pressure emulator, e.g. Torpedo PFPE, or a controller with already built-in emulator module – OPTIMA EXPERT.

  • Is it a shame to install autogas in a luxury car?

    Luxury cars are usually large and consume large quantities of fuel. Their owners can save a lot of money with a gas system. These days, no one is surprised with BMWs, Mercedes and even Maybachs, Porches and Maseratis powered by LPG. It’s hard to resist the temptation of saving money, especially when driving “four-wheeled beasts”.

    Some people believe that expensive cars must be costly in use. However, overpaying for petrol has nothing to do with the value of the car itself. Just check the after-market and the prices of luxury cars converted to gas to see that LPG does not make these vehicles any less prestigious. LPG is for smart people who manage their expenses wisely.

  • People say: save money on fuel, not on the installation of LPG. True or false?

    True. Every person who installs gas in their car does so to save money. However, you shouldn’t be looking for savings by any means. Final installation price is stems from various parameters and data (such as the model of the car as well as the type and capacity of the engine). Some of them may entail the need to install additional elements, such as the gas pressure emulator or a stronger reducer. Your car may need such additions. They will increase the cost of installation a bit, but will also ensure failure-free operation of your car. Remember, even the slightly more expensive option will pay for itself quickly as soon you’ll be paying half the price for refuelling.

  • What is the most convenient arrangement of the strategic elements of the system?

    You will figure out the arrangement of the LPG system components in your car together with the installer. It’s a good idea to think about the arrangement of such components as the gas control panel/switch (a convenient place on the dashboard or in its vicinity to keep an eye on it), the tank (possibilities are limited by car design – most frequently, the tank is placed in the spare wheel or luggage compartment or under the suspension), and the refuelling valve (it is usually placed under the fuel filler flap).

  • Periodic inspections of the system - where, how and when?

    Inspections and adjustments of the gas systems are among the basic conditions for the proper operation of the LPG system and maintaining of warranty. The schedule of inspections and replacement of various components is determined by the workshop at which the system was installed. In general, you should visit the service centre at least once a year, or after you’ve driven approx. 10,000 km (whichever will happen sooner).

  • How do I prepare a gas-powered car for winter?

    Every car, regardless of the type of its drive, should be properly prepared for the winter. Gas-powered cars should undergo a general inspection of the system and its adjustment. Adjustment may be needed due to changes in oxygen content in the air at low temperatures and because the composition of autogas is changed for the winter – the amount of propane is increased and the amount of butane – decreased.

  • How do I take care of filters in winter?

    Filters stop air pollution. Over time, filters lose their capacity, which has a negative impact on the proportions of the fuel-air mixture. In autogas-powered cars, special attention should be paid to the cleanliness and capacity of air filters. In addition, LPG systems have liquid and gaseous phase filters. Solid and liquid impurities that are accumulated in them during their use may block the flow of gas, which may hinder the operation of the LPG system. We can prevent it by changing the filters regularly. If filters are heavily contaminated, they should be replaced even before the planned periodic inspection.

  • Why do I have to check the cooling system before winter?

    In LPG-powered cars, the coolant heats up the reducer which causes gas expansion by changing its state (from liquid to volatile). For this reason, the tightness of this system should be checked before the winter season. If the cooling system becomes airlocked, the unheated evaporator will freeze under the influence of expanding gas. If there is not enough coolant in the radiator, the reducer will not operate at full capacity. Therefore, you should check the level and quality of the coolant, and refill or replace it if necessary.

  • Do I have to fill the tank with petrol in the winter?

    Of course. You cannot forget to fill up the tank with petrol, not only during the winter. After all, the engine is powered by this very fuel. Besides, if there is not enough petrol in the fuel tank, the water in the tank will condense and freeze, blocking the fuel system. To avoid this, you must fill up the tank with water to at least ¼ of its capacity.

  • What should I keep in mind when travelling abroad by an LPG-powered car?

    Before going abroad, make sure that your gas system inspection is not approaching. Check what refuelling connectors are supported at gas station in the country of your destination. Plan the route in such a way that you will always be able to refill your LPG tank. This will help you avoid searching for an autogas station later. If possible, learn what propane-butane for cars is called in the other language.