abbreviation GBO firmly in use of motorists seeking to save on fuel, but the combination of the words “gasoline HBO” often causes bewilderment among beginners. Actually, gasoline is not part of the HBO system, but serves as a reserve or starting fuel. gas equipment installed on the vehicle. Drivers often wonder why, with gas in the tank, the car still requires gasoline and how its octane number affects the gas system.
Understanding the relationship between liquid and gaseous fuels is critical to the long life of an engine. Many people mistakenly believe that after installation 4th generation GBO You can forget about the gas tank completely, but it is not. The engine control system (ECU) in certain modes of operation is forced to switch to gasoline, and the quality of this liquid directly affects the life of injectors and valves.
In this article, we will examine what lies behind the mythical “gasoline for HBO”, whether you need to overpay for high-octane varieties and how to properly adjust the transition between fuel types. You will learn the technical nuances of the work evaporator And why ignoring liquid fuel recommendations can lead to costly repairs.
Decoding of the term and the principle of operation of the system
When they say “gasoline HBO”, usually mean not some special type of fuel, and standard gasoline, which is used in a car with an installed gas cylinder unit. Gas cylinder equipment (HBO) is a set of devices that allows the internal combustion engine to run on a propane-butane mixture or methane. However, starting a cold engine and operating at high revs often require the involvement of liquid fuel.
The working principle of the modern system, for example LPG 4 generationIt is based on parallel injection. Gas is fed into the cylinders through its injectors, but at the time of start the engine is usually run on gasoline. This is necessary for heating the gearbox, which evaporates the gas. If the gearbox is cold, the gas will not go into the vapor state efficiently, which will lead to unstable engine operation.
⚠️ Attention: Attempting to start a fully heated engine on gas without preliminary heating of the gearbox can lead to freezing of condensate in the highways and failure of the gearbox membrane.
Gasoline in the HBO system performs several key functions. First, it provides an easy start in all weather. Secondly, it serves as insurance in case of sudden exhaustion of gas in the cylinder. And third, many cars use gasoline to operate at maximum power modes, where the gas mixture may not provide sufficient combustion chamber cooling or the required detonation resistance.
Effect of octane number on HBO
One of the most common questions of owners of gas cars is: “Which gasoline is better to pour – 92nd or 95th?” Octane number (OK.) characterizes the resistance of the fuel to compression self-ignition. For gas equipment, this parameter is important, since the ECU adjusts the ignition advance angle (IOC) depending on what the engine is currently running on.
Gas has a higher octane number (about 105-110 units) than regular gasoline. If the fuel with low octr is splashed in the gas tank, and the electronics do not have time to adapt correctly when switching, detonation may occur. Detonation It is an explosive combustion of a mixture that destroys pistons and rods. Therefore, the use of high-quality gasoline with an octane number recommended by the manufacturer is mandatory.
It is believed that HBO needs only 95th or even 98th gasoline. That's not exactly true. If your car was originally designed for 92nd gasoline, then the gas system, configured by a competent master, will work stably. However, if the engine is turbocharged or has a high compression ratio, switching to gasoline with a higher octane number can have a positive effect on the dynamics of the switch and the overall elasticity of the engine.
When switching from gasoline to gas, the ECU makes adjustments to the ignition angle. If the gasoline is of poor quality, corrections may be incorrect, which will cause jerks when switching modes.
It is also important to consider seasonality. In summer, the evaporation rate of gasoline is lower, and the quality requirements may differ from winter periods. In cold weather, bad gasoline can cause startup problems even before the system tries to switch to gas. Therefore, saving on fuel for a gas tank in a car with HBO is a questionable pleasure.
Modes of operation: when the engine switches to gas
Understanding the logic of switching modes helps the driver to take care of the technology. Modern systems such as DIGITRONIC or LOVATOThey have flexible transition settings. Usually the switching occurs when a certain temperature of the coolant (about 30-40 ° C) and engine speeds are reached.
At the time of launch, especially in the cold season, the engine runs exclusively on gasoline. This is necessary for heating the catalyst and lambda probe, as well as to stabilize the operation of the engine itself. As soon as the temperature of antifreeze reaches a predetermined threshold, the ECU signals the opening of gas injectors and the gradual closure of gasoline ones.
- 🚗 Cold start: Work only on gasoline until the gearbox warms up.
- 🔄 Transitional regime: Smooth replacement of gasoline with gas (lasts a few seconds).
- ⛽ Working mode: The movement is mainly on gas, the gasoline injectors are closed.
- 🏁 Full load mode: At a sharp acceleration or high speed, some systems may mix gasoline for cooling or power.
There is also an emergency gas shutdown. If the temperature sensor of the gearbox fails or the pressure in the gas main falls below the critical one, the system will automatically switch to gasoline. At this point, the driver will hear a characteristic sound and feel the change in traction. Ignoring this signal can cause you to drive to a petrol refueling station without even noticing that the gas is running out or the system is faulty.
⚠️ Warning: If the car spontaneously and frequently switches to gasoline while driving, this is a signal of a malfunction of the HBO system (clogged filters, faulty gearbox) or a critically low level of fuel in the gas tank.
Why can't you just go on the gas?
Instant gas start is only possible on special systems (LPIs) where the gas is supplied in liquid form. In classical systems, the gearbox must be heated by antifreeze to vaporize the gas. The cold gas does not mix with the air correctly, causing ignition and cotton misses in the intake manifold, which is dangerous for the engine.
Comparison of fuels: characteristics table
For clarity, compare the basic parameters of gasoline and gas to understand why the system uses both types of fuel. Differences in physicochemical properties necessitate two independent feeding systems.
| Parameter | Gasoline AI-92/95 | Propane-Bhutan (HBO) | Methane (HBO) |
|---|---|---|---|
| Aggregate state | Fluid | Liquefied gas | Compressed gas |
| Octane number | 92-95 | 105-110 | 120 |
| Flamming temperature | Tall. | Tall. | Very high. |
| Burning temperature | ~1200°C | ~1100°C | ~1150°C |
| Impact on oil | Liquidating butter | It doesn't liquefy (dry) | It doesn't liquefy (dry) |
The table shows that the gas burns at a higher temperature, but has a lower combustion temperature in the cylinder, which reduces the heat load on the parts. However, gas does not lubricate the valve seats, unlike gasoline, the vapors of which create a protective film. That is why special engines with HBO are recommended spark-plug And more frequent oil change.
It is also worth noting the effect on motor oil. Gasoline, getting into the crankcase (especially on frequent short trips), dilutes the oil, reducing its protective properties. Gas, on the contrary, does not mix with oil, maintaining its viscosity, but contributes to faster oxidation and carbon monoxide. Therefore, the intervals of oil change on cars with HBO are often reduced by 20-30%.
The presence of gasoline in the tank of a car with HBO is necessary not only as a reserve, but also to ensure the correct lubrication of the valve mechanism in certain engine operating modes.
Typical problems and diagnosis
Operation of a car with HBO requires attention to the state of both fuel supply systems. Often the problems drivers attribute to the quality of the gas actually lie in the gasoline system. For example, if the car is not started well or stalls on singles, the first thing you need to check is fuel-pump and fuel-nozzle.
One of the common problems is the “forgetting” of gasoline. Drivers get used to driving on gas and do not monitor the level in the gas tank. Gasoline tends to age: after 6-12 months, it loses its properties, oxidizes and precipitates. This can lead to clogging of the gas pump grid and its failure at the most inopportune moment when the system tries to switch to liquid fuel.
Diagnosis of the HBO system often shows errors related to the composition of the mixture. If the lambda probe detects diminution or re-enrichment, this can be caused by both a malfunction of the gas gearbox and an air sucker in the intake manifold, which was compensated differently in gasoline modes. Therefore, when setting up the HBO master should always check the serviceability of the gasoline system.
☑️ System check before winter season
Operation and maintenance rules
For the bundle of "gasoline + HBO" to work long and reliably, you need to follow a number of simple but important rules. Ignoring them leads to accelerated engine wear and expensive repairs.
First of all, never let the gas tank completely empty. Always keep a minimum of 10 liters of quality gasoline in the tank. This will save the gas pump from overheating (it is cooled by fuel) and ensure a guaranteed start of the engine in the cold. In addition, this will allow the system to conduct a self-test of gasoline injectors.
The second rule is about warming up. In winter, let the engine warm up on gasoline to operating temperature before switching to gas. A sharp start on gas without warming up the gearbox is unacceptable. It is also recommended to periodically (once every couple of days) forcefully switch to gasoline to “develop” the gasoline system and prevent the nozzles from coking.
⚠️ Note: Do not attempt to set up the LPG yourself without a gas analyzer. The wrong mixture will either lead to over-use of fuel, or to burnout of the valves and melting of the pistons.
Regular maintenance should include replacement of gas filters (every 10-15 thousand km), checking the tightness of the connections and diagnosis of spark plugs. For HBO it is better to use candles with an increased gap and a potassium number one above the standard, since the gas requires a more powerful spark.
How often do you change the oil in the engine with HBO?
The recommended interval for oil change for cars with HBO is 7-8 thousand kilometers, even if the manufacturer allows 15 thousand. Gas fuel contributes to more intensive oxidation of oil, so frequent replacement will prolong the life of the engine.
Frequently Asked Questions (FAQ)
Can I completely remove the gasoline from the car?
Technically, this is only possible on 5th and 6th generation (LPI) systems, where the gas is supplied in liquid form, and then with limitations. On the classic 4th generation HBO, it is impossible to remove the gas tank: the system will not be able to start the cold engine, and also lose the ability to emergency switch. In addition, the ECU can issue errors on gasoline injectors.
Why does the car twitch when switching to gas?
There may be several reasons: low temperature of the gearbox, low gas pressure, contaminated gas injectors or incorrect calibration of the switching card. Also, jerks are possible when using old gasoline, which does not burn correctly at the time of transition.
Does the LPG damage the engine life?
With proper tuning and quality maintenance, the engine life is reduced slightly (by about 5-10% due to increased heat load). The main risk is the burn of the valves with a poor mixture. The use of quality components and timely oil replacement minimize the risks.
Which petrol is better to pour: 92 or 95?
Use the gasoline recommended by the manufacturer of your car. If the engine is designed for the 92nd, then the 95th will not give a significant increase, and if the 95th - then pouring the 92nd is dangerous because of the risk of detonation, especially at the time of switching to gas.
Do I need to warm up the car before going on gas?
Yes, it's a must. The engine must warm up to the temperature of the cooling fan (or at least to 40-50 degrees) so that the HBO reducer heats up from antifreeze and begins to properly evaporate the gas.