BMW fuel consumption can be reduced

BMW FUEL ACTIVATOR — a device which is installed on a fuel hose of any BMW car and significantly reduces fuel consumption BMW by 20% and improves the engine performance. Therefore, with the same amount of fuel on your BMW, you will drive MORE KILOMETERS!

Activators on BMW fully pay off in 3-4 months!
The service life of Activators for BMW is 10-15 years.

reduced fuel consumption BMW

Activators are installed on all models of BMW and are used in all types of fuel — GAS, PETROL, DIESEL FUEL.

The activators are easy to install, they are installed on the BMW fuel supply hose in a few minutes:

1. BMW fuel consumption is reduced by 20%.
2. A slight increase in the power of the BMW engine.
3. Extends the service life of the BMW engine.
4. The content of carbon monoxide and other pollutants in BMW exhaust gases is reduced by 30-40%.
5. Stable and dynamic operation of the BMW engine.
6. Reduces the formation of soot and carbon deposits on BMW pistons, cylinders, spark plugs, fuel injectors, catalyst and exhaust pipes.
7. Extends the service life of the BMW catalyst, lambda probe, spark plugs and BMW fuel injectors.

BMW ACTIVATOR reduces fuel consumption by 20%.

At the same time, the engine operation of BMW is significantly improved.

Examples of installation on different models of BMW.

Click on the photos, to enlarge

ANY FUEL (petrol, diesel, gas), by going through 10 magnetic fields of THESE ACTIVATORS, for a short time changes its structure and properties, and it BURNS more fully and REGULARLY.
Due to this, the BMW engine begins to work much BETTER.

Usually, it is already seen after 10-20 km of run of the car BMW which has an installed Activator.

Imagine, how your BMW engine works with VERY GOOD FUEL
That is, we have quite different (better) fuel.

operation of the fuel activator BMW

     You agree that chopped firewood burns much better than whole logs … The same thing happens with automotive fuel in the cylinders of the BMW engine.

fuel economy

car fuel economy

Activators installed on BMW reduce the density and viscosity of fuel:

1. This leads to the formation of smaller fuel particles, ensures good atomization and combustion in the cylinders of the BMW engine.
2. The fuel ignites better and burns smoothly, ensuring soft and smokeless operation of the BMW engine.
3. Reduces deposits on injectors and carbon deposits on candles and BMW cylinders.
4. Reduces the load on the operation of BMW fuel supply systems.
5. Increases reliability and increases the life of BMW fuel equipment.

All this leads to improved conditions for fuel combustion in BMW cylinders.

    FUEL with Activators burns more completely in the BMW engine, does not leave carbon deposits on pistons, cylinders and spark plugs.

     On BMW diesel cars, the injectors are not polluted, and there is no black smoke even at throttling at free running.

fuel engine operation BMW

Knowing where the fuel hoses are located, Activators at BMW are installed within 5 minutes (see «INSTALLATION»)

     ATTENTION! The main difference of THESE ACTIVATORS is that there are 20 magnets placed in them, which for a short time CHANGE THE STRUCTURE AND PROPERTIES OF FUEL.    In other similar Aktivators which can be used on BMW, there are only 2 powerful magnets which are not able to change anything in the fuel (see «ANALOGUES» ).

     When you don’t like the Aktivators, then with no doubt you can return them back within 30 days (read «RETURN»).

ACTIVATOR reduces the fuel consumption of any BMW vehicle by 20%. Therefore, with the same amount of fuel on your BMW, you will drive MORE KILOMETERS!

The operating life is at least 15 years
We produce and sell them starting from 2008

PRICE:

The set of Activators (2 Activators) — 60,00 EUR

reduced fuel consumption for BMW

The price includes the deliver by post.

NOVELTY

When installing on BMW both the Fuel combustion Activators and Activator Autothermia, FUEL CONSUMPTION is reduced by 30-40%!

Read «ACTIVATOR OF AUTOTHERMIE»

fuel engine operation BMW

PATENTS
(click on the image, to enlarge it)

scientific documents on fuel consumption BMW

17 real tips on how to reduce BMW fuel consumption.

   Fuel consumption is one of the biggest items of expenditure for motorists, which takes a tidy sum from the budget every month. BMW’s fuel consumption depends on a variety of components. We cannot influence some of them in any way (for example, engine power). Therefore, it is worth first finding out what BMW’s fuel consumption is standard for a particular make and model, so that there will be no surprises later.. The other part of the components, with a competent approach, can significantly reduce BMW’s fuel consumption, and therefore reduce the cost of operating the car.

1. Smooth acceleration reduces BMW fuel consumption

   According to experts, up to 60% of BMW’s fuel consumption depends on the driver, or rather on his driving style. One of the most effective ways to reduce BMW fuel consumption is smooth acceleration. With sudden acceleration and braking, some of the fuel simply flies out into the «pipe». Smooth driving, especially in the city, allows you to save a significant amount of fuel. The dependence here is simple – the less we press on the gas pedal, the less BMW fuel is consumed.

2. Choosing the right gear reduces BMW’s fuel consumption

   Timely switching to higher gears, prolonged acceleration in each gear increases BMW’s fuel consumption. The optimal operating mode of most modern engines is a range from 2 to 3 thousand revolutions, when driving at lower or higher speeds, BMW fuel consumption and engine wear increase. If possible, turn on high gear — this is usually the most economical.

3. Engine braking reduces BMW fuel consumption

   Another trick is to use engine braking instead of rolling. When coasting, the engine is idling and in any case consumes a certain amount of fuel. When the engine brakes, the car’s electronics «sees» that the engine speed is high and the gas pedal is released, and turns off the fuel supply. That is, the engine operates in compressor mode and does not consume fuel. If the BMW fuel consumption is displayed on the on-board computer display at this moment, it will be equal to 0 liters.

4. Frequent stops increase BMW’s fuel consumption

   Drive in such a way as to minimize vehicle stops. Analyze the traffic light signals in advance — if the red light is on, you can slow down and drive up to the traffic light, when the green light turns on, you can drive through the intersection without stopping. The same applies to pedestrian crossings — there is no need to accelerate if you see pedestrians approaching the crossing. Each stop and subsequent start from the spot increases BMW’s fuel consumption.

5. Frequent engine starts increase BMW fuel consumption

   Do not turn off the engine during short stops for 1-2 minutes. Starting the engine will require additional BMW fuel consumption. Turn off the engine when stopped in traffic for more than 5 minutes. If the stopping time is less than 5 minutes, constant engine starts and stops will not only increase BMW’s fuel consumption, but also shorten the life of the battery and starter. The exception is cars with a «Start-stop» system, the units of which are designed for such work.

6. Overtaking other cars increases BMW’s fuel consumption

   Avoid unnecessary overtaking. With dynamic overtaking, BMW’s fuel consumption increases dramatically. If you need to turn onto a nearby road or stop at a gas station immediately after overtaking, you should not overtake for the sake of overtaking.

7. Prolonged engine warm-up increases BMW fuel consumption

   In the cold season, do not warm up the engine while standing still. With prolonged warming up, BMW’s fuel consumption increases, and the engine warms up much faster on the go. It is enough to start the car, warm it up for a couple of minutes and slowly start driving at low engine speeds.

8. Open windows increase BMW fuel consumption

   Open windows and hatches create additional aerodynamic drag and increase BMW fuel consumption. Therefore, if weather conditions allow, it is better to close the windows and use the car’s heating system fan to supply air.

9. The included air conditioner increases BMW’s fuel consumption

   With the air conditioner on, BMW’s fuel consumption increases to 15%, but here everyone chooses for themselves between comfort and fuel consumption. In addition, in conjunction with the previous advice, you need to understand that in conditions of long-term high-speed traffic on the highway, it will still be more economical to turn on the air conditioner than to drive with the windows open. At high speeds, aerodynamics have a more serious impact on BMW’s fuel consumption.

10. Reducing the weight of the car reduces BMW’s fuel consumption

   The heavier the car, the greater the BMW’s fuel consumption. To reduce BMW fuel consumption, you can unload the trunk by removing unnecessary things from it: oil cans, antifreeze, spare parts, etc. There may also be things in the cabin that are just lying around. For example, a car seat. Taken together, these little things can significantly reduce the excess weight of a BMW car.

11. Tires and rims affect BMW fuel consumption

   To reduce BMW’s fuel consumption, you need to pay more attention to the choice of tires. Modern high-quality tires reduce rolling friction and help to further reduce BMW’s fuel consumption. Usually, immediately after installing new tires, BMW’s fuel consumption increases and then gradually decreases. Reduced tire pressure increases BMW’s fuel consumption as rolling resistance increases. However, it is not necessary to increase tire pressure too much to save fuel, as this can negatively affect handling and comfort. It is sufficient to maintain a constant pressure recommended by the manufacturer for a given tire size. As for the discs, the dependence is simple — the wider and heavier the discs, the higher the BMW’s fuel consumption. Using alloy wheels (cast or forged) instead of stamped ones allows BMW to save fuel.

12. The included headlights increase BMW fuel consumption

   They create an additional load and increase BMW’s fuel consumption, however, if you do not have daytime running lights installed, then by law you are required to turn on the headlights at any time of the day, so we cannot influence this factor.

13. The heater and preheating affect BMW fuel consumption

   Powerful sources of load on the vehicle’s on-board network also contribute to an increase in BMW fuel consumption. This is a heater, heated seats, mirrors, windows. Therefore, it is worth using them exactly as much as it is really necessary.

14. Roof rack increases BMW fuel consumption

   Aerodynamics have a greater effect on BMW’s fuel consumption on the track – the higher the speed, the stronger its influence. It is clear that we cannot fix the factory aerodynamics. However, additional elements, especially the roof rack, can worsen it. If you don’t need it specifically on this trip, it’s better to take it off.

15. Analysis of the on-board computer readings will help determine the optimal fuel consumption of BMW

   If your BMW car is equipped with a route computer, switch it to the BMW fuel consumption reading mode. By monitoring fuel consumption, you can choose the most optimal driving mode.

16. The condition of the car affects BMW’s fuel consumption

To reduce BMW’s fuel consumption, it is necessary to maintain the car on time and change consumables. For example, contaminated air and fuel filters, old spark plugs can lead to increased BMW fuel consumption.

17. The choice of engine oil affects BMW’s fuel consumption

If the BMW car manufacturer allows the use of several variants of engine and transmission oils, use the least viscous ones, they will help reduce BMW fuel consumption

The general structure of the BMW car

   The general design of a BMW car used to be taught in a driving school. But today, many, even some experienced drivers have no idea what a BMW car is made of. We decided to fill in these gaps and prepared a short explanation of the main parts of a BMW car. In the meantime, let’s tell you what is responsible for what in a BMW car — for beginners.

BMW car body

   This is the main component of any car. Some people think that the body is about trucks and vans, but this is not the case. In BMW passenger cars, a body is called a metal base, to which all other components and parts are attached. And this is not the metal that we see from the outside (doors, hood, fenders). The main part of the BMW body is its power structure, not the attachments. You can see her too. For example, if you open the hood and look at the wall between the engine and the cabin. It is called the BMW motor shield, it also belongs to the power structure.

   Making a solid but lightweight spatial (three—dimensional) body structure is not an easy task. Therefore, at the dawn of motorization, a simpler solution was used — a frame consisting of a pair of powerful longitudinal profiles of rectangular cross-section and several transverse ones. If you put such a frame vertically, it will look like a large ladder. The engine and everything else were attached to the frame, including a simpler body, which could even be made of wood. Over time, the frame remained only for SUVs (and not all of them) and commercial vehicles.

   The body is needed not only for placement inside the units of a BMW car and passengers with cargo. It is also the most important element of passive safety. Modern BMW bodies are designed so that in case of an accident, they extinguish the impact energy due to deformation of the «technical zones» — the engine compartment, thresholds, etc. The interior is made a solid «cage», which should not allow deformation, protecting passengers. So if you see a severe deformation of the front of the car after an accident, it does not mean that it is «cardboard». On the contrary, the BMW body structure worked as it should and prevented the driver and passengers from serious overloads.

BMW suspension

   Even horse-drawn carriages had primitive suspension. In a BMW car, this term refers to the parts that connect the body and wheels. The suspension in the BMW car has several tasks at once.

   Initially, the suspension was used to compensate for the irregularities of the road. The main role in this is played by elastic elements (springs, springs, etc.) and shock absorbers. But in addition to the comfort of the driver and passengers, the suspension must ensure the closest possible contact between the wheels (tires) and the road. Security depends on it. If the wheel bounces on each bump and loses grip on the surface, the BMW car will not be able to confidently keep the direction of movement, and in turns it will begin to demolish and skid. Braking will also be ineffective, because contact with the coating is constantly lost. So a good suspension in the design of a BMW car should be moderately rigid to ensure reliable traction of the wheels with the road, and moderately soft so as not to shake the driver and passengers.

BMW steering

   There should probably be no questions here. With the help of the steering system of the BMW car, we set the direction of movement. In the most familiar version, the command from the steering wheel passes through an electric or hydraulic amplifier, a steering mechanism (today most often in the form of a gear and a rack) and with the help of a traction system turns the front wheels to the desired angle. But there are also more modern systems. There is no direct mechanical connection between the steering wheel and the wheels. The BMW driver, by rotating the steering wheel, only sets his intentions, which are read by sensors. And a separate electric motor controls the rotation of the wheels.

   What should I do if this motor fails? It is clear that such a BMW malfunction is very dangerous — therefore, the system will switch to emergency mode by connecting the steering shaft, and the steering scheme will return to the classic one.

BMW brake system

   A BMW car needs not only to accelerate, but also to stop effectively. Braking mechanisms in each BMW wheel are responsible for deceleration. And they are controlled by a hydraulic (liquid-filled) system. The driver, pressing the brake pedal, creates pressure in it. If necessary, it is increased by a special amplifier, and then it is transmitted through metal tubes and rubber hoses to the brake mechanisms of the BMW wheels.

   Of course, this is a highly simplified version that was used in BMW models of the last century. A modern BMW car can have an electronic braking system. The principle is the same as with electronic steering: sensors, control unit and electric pump instead of direct mechanical communication. This allows the BMW car to brake before the driver’s command, if necessary — in emergency situations. And most importantly, it is more accurate and safer to distribute the braking force on the BMW wheels.

   In addition, even low-cost BMW models now have an anti-lock braking system. It monitors the pressure in the system, the rotation of the wheels and prevents them from locking even with a strong pressure on the brake pedal. As a result, the BMW car retains controllability (with the wheels locked, it simply slides in the same direction, sometimes also rotating), and this makes it possible to avoid an obstacle. BMW’s braking system is also used by other electronic assistants. For example, this is how ESP works — it is the brakes that stabilize the BMW car.

   A separate element of the BMW brake system is the parking (manual) brake. As its name implies, it is designed to fix a BMW car while parking. On the move, it is used only as an emergency one — in case of failure of the main brakes. It can also have a mechanical design (then it is actuated by a lever that clamps the disc or drum with pads) or be electrically actuated by pressing a button.

BMW engine

   Otherwise, it is also called a power unit, although this is not entirely true — in fact, this term combines a motor and a gearbox (more on it later). Traditionally, BMW cars use internal combustion engines, in which the energy of the burning fuel is transformed into mechanical energy using certain mechanisms, and it drives the wheels of the BMW. And some of it is also electrical, due to the operation of the BMW generator.

   Today, you will not surprise anyone with a BMW electric motor. It doesn’t need fuel, it runs on battery power. BMW hybrid cars also remain very relevant. These have both engines (or even several electric ones). But in hybrids, the battery capacity is relatively small. It is enough to drive at low speed for several kilometers, and then the engine starts and it already moves the car, while charging the batteries. Why such difficulties? The fact is that the hybrid turns out to be more efficient than the traditional design — at least because it allows you to return some of the energy spent on acceleration during subsequent braking of the BMW car. This mode is called recuperation, in which an electric motor turns into an electric power generator. And the engine itself, due to the help of an electric motor, operates in more economical modes.

BMW Power Supply System

   To properly understand how the internal combustion engine works in a BMW car, it is important to know that the engine needs more than just fuel. To burn it, you need air — and in a strictly defined amount. The BMW power supply system is engaged in preparing its mixture with fuel and feeding it into the cylinders.

   The device of a BMW passenger car of the last century assumed the presence of a carburetor for making a mixture. Then the carburetors were replaced by fuel injection systems — they are installed on all modern cars. The mixing process is handled by electronics. It receives signals from various sensors (including the oxygen sensor in the exhaust system), calculates the optimal composition of the mixture. With distributed injection, the injectors, at the command of the control unit, supply the required amount of fuel to the intake manifold, where it mixes with air and enters the BMW cylinder.

   There are also direct injection systems. In them, the fuel enters directly into the BMW cylinders and is already mixed with air from the BMW intake manifold there. But the principle is the same: a mixture of the desired composition is formed in the BMW cylinders, and it ignites.

BMW exhaust system

   It is also called exhaust. Only BMW internal combustion engines have it. After the fuel-air mixture has burned in the BMW cylinders, it is necessary to remove the formed gases as quickly as possible. And at the same time reduce the noise from their escaping flow. These are the main tasks of the BMW exhaust system. It usually consists of several components — neutralizers, resonators and silencers. Once in them, the gases cool down, and sound waves passing through a system of channels with partitions partially compensate each other. As a result, at the outlet of the pipe we do not get a red-hot exhaust with a terrifying roar, but only warm gases with a tolerable soundtrack.
If we talk about modern BMW exhaust systems, they have one more important detail — a catalytic converter. It decomposes the harmful components of exhaust gases into more harmless ones — ideally, nitrogen, water and carbon dioxide. Read what a BMW catalyst is and how it works.

BMW transmission

   This is all that transmits the rotation of the BMW engine to the wheels. Again about the popular misconception. The transmission is not just a gearbox that converts the torque developed by the motor. In addition to the box itself, there are also shafts that connect it to the drive axles, gearboxes that transmit torque further to the wheels, hinges of equal angular velocities.

   There are several types of drive (front, rear, full), different versions of BMW gearboxes (manual, automatic, CVT, robot), as well as BMW transfer cases. Depending on this, the types of transmissions also differ, although they are conditionally divided according to the type of BMW gearbox.

BMW Electrical Equipment

   Even in the simplest BMW car, there are many consumers of electricity. These are spark plugs (they need to be supplied with current to create a spark), headlights, electric fans, and windscreen wipers. Modern BMW models are simply packed with electronics.

   There are two «suppliers» of energy in a BMW car: a battery and a generator. The BMW battery stores current and outputs it when the BMW engine is started. We also use it when parking with the BMW engine turned off: for example, if we turn on the emergency light or listen to music.

   But the energy reserve in the BMW battery is not so great. Therefore, after starting the BMW engine, the BMW generator takes over the task of supplying the on-board system with electricity. This is a mini-power plant that converts the rotational energy of the engine into electrical energy. Energy is consumed, among other things, to replenish the battery capacity of the BMW.

18 Ways to Save fuel consumption BMW

There are a huge number of very different ways to save BMW fuel, most of which motorists often do not even realize. Meanwhile, following these simple tips will save the lion’s share of the budget spent on BMW fuel.

Method 1 — the fuel consumption BMW car needs to be inspected periodically

First you need to inspect the air filter by visual inspection. Such a simple operation can be done with a car of any BMW brand. If the working surface of the filter is noticeably dirty, this can significantly hinder the flow of air into the engine, which will cause increased BMW fuel consumption. It is necessary to replace the filter – this procedure takes a minimum of time and does not require professional help.

Method 2 — it is necessary to choose the right oil for fuel consumption BMW

It is possible to reduce BMW’s fuel consumption by choosing the right engine oil. During the combustion of the fuel mixture, most of the important components of the car move. With poor oil quality, strong friction occurs between the parts, which affects the increase in energy consumption, and consequently significantly increases BMW fuel costs. Therefore, it is so important to choose the oil without mistakes, taking into account all the details: viscosity, age of the car, features of operation.

Method 3 — Proper fuel consumption BMW traffic during rush hour

It is at this time that motorists often have to stand with the engine running. It is important to brake in advance when approaching a traffic light. Thus, it will be possible to come to the traffic light on the roll.

Method 4 — the style of travel is important fuel consumption BMW

Often, the driving style with too sudden acceleration and braking at excessive speeds (this style of driving a car is also called sports) leads to a significant increase in BMW fuel consumption. It is equally important to avoid increased gears when driving at low speed. It is necessary to keep the location of the tachometer needle under control.

Method 5 — you need to track the pressure in the fuel consumption BMW tires

Those who have been driving for years know exactly how the air pressure in the tires affects BMW fuel consumption. It is important to monitor the water indicator every time before a trip. The maximum pressure can be exceeded by 0.2 atm from the value recommended by the manufacturer. If the wheels are poorly inflated, the consumption of any BMW fuel during the trip will increase. Manufacturers always clearly regulate the level of tire pressure on the rear, front axle.

With poorly inflated wheels, there will be resistance to movement as a result — BMW fuel consumption will increase.

Method 6 — Monitor the status of all working fuel consumption BMW devices

A working air conditioning device increases BMW fuel consumption, which is not always justified. Working headlights, car radio, heater burn BMW fuel no less.

Method 7 — you can get rid of some decorative elements BMW

Few motorists know that individual tuning elements also reduce BMW’s fuel economy. So, the increased aerodynamic drag greatly increases BMW fuel consumption. The same applies to large spatial body kits and enlarged disks.

Method 8 — the right choice of BMW brand

Everyone knows that the use of expensive gasoline with a high octane number can significantly improve the dynamic characteristics of a car. At the same time, BMW fuel consumption is noticeably increasing. To save money, you should read the instructions of the automaker. Most likely, gasoline with the lowest octane number can be used for your car. As a rule, the older the car, the simpler the fuel (with the lowest octane number) he needs.

Method 9 — take into account the weight of the BMW car

The weight of the car often affects BMW fuel consumption. Experienced car owners know how to reduce fuel consumption by controlling the weight of the car. Cars with low weight consume fuel several times less than their heavier counterparts. At the same time, it is often enough to remove all things from the luggage compartment in order to reduce BMW’s fuel consumption, thereby reducing the weight of the car.

Method 10 — choose a manual transmission BMW instead of an automatic one

If you are determined to reduce BMW fuel consumption, choose a car with a manual transmission. automatic usually increases BMW fuel consumption by at least 15 percent.

Method 11 — Refuse to ventilate the BMW

Those who like to open windows while driving for better ventilation of the cabin, it is necessary to take into account that this creates additional resistance to movement. As a result of this overcoming of aerodynamic drag, the motor requires additional power. Therefore, to save BMW fuel, it is necessary to close the windows while driving.

Method 12 — installation of fuel consumption BMW gas equipment

There is one traditional method of saving fuel consumption – switching the car to work on gas. Such retrofitting will significantly reduce BMW’s fuel costs. At the same time, the noise level will noticeably decrease, the exhaust will be cleaner, and the engine will start working much softer. However, it is necessary to take into account the disadvantages that arise as a result of such manipulation: the trunk volume will be reduced, the driving dynamics will decrease. Simultaneously with this, the acceleration speed decreases.

Method 13 — Track the speed mode

It is necessary to keep under control the frequency of the crankshaft recommended by the car manufacturer in accordance with the speed selected at the same time. Movement at exceeded crankshaft speeds increases BMW fuel consumption, which is needed for the engine to work.

Method 14 — organize a joint trip

When you travel to work or study on the same route every day, you can always take fellow travelers with you in the person of acquaintances, friends or colleagues. If you divide the cost of BMW fuel for everyone, it will not be expensive at all, and you can save great money. The same applies to country trips.

Method 15 — it is important to insulate the BMW engine

With the onset of cold weather, it is necessary to take care of good insulation of the power unit, which will allow you to significantly reduce the time it takes to warm it up. After all, the speed of warming up a car directly affects BMW fuel consumption. For heating, it is not necessary to use blankets that easily catch fire. Today, manufacturers offer special compact heaters that perfectly retain heat and resist the effects of high and too low temperatures. The use of such devices makes it possible for a long time to maintain the right temperature for a heated motor when you get out of the car on business.

Method 16 — use self-contained heaters

When the temperature is below zero outside, motorists are forced to switch to increased engine heating. To put the engine of a car that has been standing in the cold for some time into operation, additional BMW fuel consumption is required. At the same time, a cold start can greatly reduce the life of the engine. Alternatively, you can use a special car fan, which allows you to completely solve the problem of starting the power unit in the cold season. For help in installing such a fan heater, it is advisable to contact professionals, since the electrical network of the car is involved for its operation.

Method 17 — Avoid aggressive driving style

Sudden braking, pressing on the gas, driving jerkily — all this leads to the fact that BMW’s fuel consumption increases significantly. To save fuel, BMW should definitely reconsider the driving style.

Method 18 — choose BMW tires by season

BMW fuel consumption is also affected by the width of the tire tread. The wider the tread, the greater the BMW’s fuel consumption.

 

BMW. Reducir el consumo de combustible bmw