fuel


 * Fuel Efficiency**

What are fuel efficient systems? Fuel efficiency is a world-wide issue, because the gasses which cars don't burn go to the air people breath and become a part of polution. Moreover, these gasses add up to the green house effect, which is another huge issue all around the world as well. To reduce the outcome of these gasses from the cars, people have developed efficient engines, that burn much less fuel in a more efficient way, therefore less gasses come out of the vehicle. To make the engine efficient, the engineers had to add special features to the engines, such as special software and sensors, that control the injection of the gass, etc. What exactly these sensors are and what is their function: Engine Sensors In order to provide the correct amount of fuel for every operating condition, the engine control unit **ECU** has to monitor a huge number of input sensors. Here are just a few: Mass airflow sensor - Tells the ECU the mass of air entering the engine
 * Oxygen sensor(s)** - Monitors the amount of oxygen in the exhaust so the ECU can determine how rich or lean the fuel mixture is and make adjustments accordingly
 * Throttle position sensor** - Monitors the throttle valve position (which determines how much air goes into the engine) so the ECU can respond quickly to changes, increasing or decreasing the fuel rate as necessary
 * Coolant temperature sensor** - Allows the ECU to determine when the engine has reached its proper operating temperature
 * Voltage sensor** - Monitors the system voltage in the car so the ECU can raise the idle speed if voltage is dropping (which would indicate a high electrical load)
 * Manifold absolute pressure sensor** - Monitors the pressure of the air in the intake manifold The amount of air being drawn into the engine is a good indication of how much power it is producing; and the more air that goes into the engine, the lower the manifold pressure, so this reading is used to gauge how much power is being produced.
 * Engine speed sensor** - Monitors engine speed, which is one of the factors used to calculate the pulse width There are two main types of control for multi-port systems: The fuel injectors can all open at the same time, or each one can open just before the intake valve for its cylinder opens (this is called sequential multi-port fuel injection). The advantage of sequential fuel injection is that if the driver makes a sudden change, the system can respond more quickly because from the time the change is made, it only has to wait only until the next intake valve opens, instead of for the next complete revolution of the engine.
 * How exactly ECU works:** The ECU receives a wide number of sensor readings from all over the engine. Built into the ECU is a fuelling and ignition map which is basically a gigantic table of numbers. It's like a lookup table that the ECU uses to determine injector pulse width, spark timing (and on some engines, the variable valve timing). So the ECU receives a set of values from all its sensors, which it then looks up in the fuelling and ignition map. At the point where all these numbers coincide, there is final number which the **ECU** then uses to set the injector pulse width.

Social and Ethical Issues:
 * Even if you don't have a fuel efficient engine, here are some types of how to reduce the cars gas cosumption:** **Use your gears wisely**. Driving in the highest gear possible without laboring the engine is a fuel-efficient way of driving.A vehicle traveling at 60kmph in third gear uses 25 percent more fuel than at the same speed in fifth gear.
 * Drive smoothly** Think ahead! By applying light throttle and avoiding heavy braking, you can reduce both fuel consumption and wear and tear. Try to predict traffic at junctions and when in queuing to avoid accelerating and then braking. Research suggests driving techniques can influence car fuel efficiency by as much as 30%.
 * Advantages of fuel efficient engines:** -fuel is being burned more efficiently than in normal engines(less emissions) -less gas consumption, therefore money saving -environment friendly
 * Disadvantages of fuel efficient engines:** -high initial costs -more expensive to maintain and repair
 * Reliability:** Even though the efficient engines are very reliable, their disadvantage is that if they need to be repaired, the costs are much higher than when repairing a normal engine. The sensors are very reliable, because the car manufacturers use the newest IT technology for their vehicles.
 * Equality of Access:** Because fuel efficient engines are more expensive, some people don’t have the to for buy them and the maintenance of efficient engines is higher than the maintenance of normal engines.
 * Globalization and Cultural Diversity:** It’s worldwide know, that pollution is a huge problem that has to be solved and most of the countries are a part of a worldwide group that is trying to take over this problem solving by sponsoring fuel efficient engines, so even lower class families can afford buying a car with a fuel efficient engine.
 * Control:** The car manufacturer has the control over the vehicle, but it is very easy to replace the chips or sensors, so the owner of the vehicle can adjust the cars' performance depending on his specific needs, such as adding horsepower.
 * Policies and standards:** The manufacturer has a special format and criteria for the efficient engines, so the car doesn't produce more gasses than the limit set by the governement or country is.
 * People and Machines:** In this case, technology is used appropriately. The design is safe and very effective. The fuel efficient engines are a very good example of innovation of technology.