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US President Barack Obama made the first big green move of his Administration by simply getting out of the way. Speaking from the White House, the President on Monday announced that he was directing the Environmental Protection Agency (EPA) to reconsider an application by California and 13 other states to set stricter limits on greenhouse-gas emissions from cars and trucks, opening the way for tighter fuel efficiency standards nationwide. Obama is also directing the Department of Transportation to issue guidelines that will ensure the U.S. auto fleet reaches an average fuel economy of 35 miles per gallon (m.p.g.) by 2020 at the latest.

The best keep secret is that higher fuel efficiency is possible today. Greater fuel efficiency has been controlled since the introduction of the fuel injection engines and the ECM (engine control module). The Engine Control Unit or ECU is a designated computer that was developed to manage the engine control system. The ECM consists of electronics which are mounted on a multi-layer circuit board. The ECM monitors and adjusts the air/fuel mixture and utilizes a catalytic converter to minimize the amount of pollution produced from the engine. There are two modes of operation, closed loop, which means the computer has completely taking over the operation system. And open loop which is used when the engine is cold and operates on a preset program. The engine must be at operating temperature before it can go into closed loop.

The ECM monitors the input and output signals produced by various sensors in the system. The ECM then adjusts the system as necessary. Sensors include: O2 (oxygen) sensor, coolant sensor, mass air flow sensor, air intake sensor, crankshaft angle sensor, throttle position sensor, camshaft angle sensor and knock sensor. The ECM operating program consists of information cells. These cells hold the code for controlled engine operation.

The ECM outputs a 5 volt reference to most sensors to regulate the monitoring circuits. The ECM also controls the radiator cooling fan, air pump controls, fuel pump, EVAP system and more depending on the vehicle. The main purpose of the ECM is to control the vehicle’s air/ fuel mixture, to maintain a factory set air to fuel mixture ratio so that the vehicle fuel consumption is controlled to low fuel efficiency standards. The car makers have controlled the fuel efficiency of their vehicles by setting the air/fuel mixture ratio to be 14.7 : 1.

All modern vehicles have O2 sensors. The O2 sensor produces its own voltage, which makes it a type of generator. The generated varying voltage shows up on the scope as the familiar 1 Hz sine wave, when in closed loop (engine is at operating temperature). The actual voltage that is generated is the difference between the O2 content of the exhaust and that of the surrounding ambient air. The stoichiometric air-fuel ratio or the mixture of air-to-fuel is programmed by the vehicle manufacturer to equal to 14.7:1. The car manufacturers state that at this ratio the engine combustion process happens with the most power being generated and the least amount of emissions being produced. At a stoichiometric air-fuel ratio (14.7:1), the generated O2 sensor voltage is preset to about 450 mV. The Engine Control Module (ECM) is programmed to view a value above the 450 mV as a rich condition, and a lean condition below it. The ECM adjusts the fuel injector pulse width to achieve the factory set mixture, as determined by the O2 sensor. When the O2 gets too RICH, it will always and automatically decrease the injector pulse width allowing less fuel to be injected into the engine, if it gets too LEAN, it’s always and automatically increase the amount of fuel injected in the engine.

The vehicle’s Air mass meters, controlled by the ECM, also determines how much fuel is or isn’t used in the combustion. A set electric signal is applied to a special alloy wire that is suspended in the middle of the air flow to the engine and depending upon how much air passes across that wire, it presents an impedence to the flow of the signal and the ECM then uses this signal to determine how much fuel is required to meet the 14.7:7 air to fuel mixture ratio.

In both cases a voltage controls the air to fuel mixture so that it will always be the same - 14.7:1 or low fuel efficiency. The secret to greater fuel efficiency is to change the voltage so that the vehicle runs leaner - leaner meaning less fuel is being used. Even a slight adjustment to the voltage will result in much better fuel efficiency. The trick is to adjust the voltage by reducing the voltage just enough as to not reduce the fuel flow to such extremes as to starve the engine for fuel. There are many ways to quickly and cheaply reduce the voltage output to the vehicle’s O2 sensors and Air mass meter.

Another secret to increased fuel efficiency is to bypass the vehicle’s air mass metering. Air bypass lets unmetered air into the intake manifold. The computer does not “know” about this air and thus does not match it with its preset air fuel mixture ration. The more air you allow to bypass, the less fuel will be automatically injected by the ECM to meet the 14.7:1 low fuel efficiency protocols. Bypassing the air mass metering system rather than reducing the air flow before the air mass metering system will insure that the engine receives more air than required for a good combustion. If you were to restrict the air flow before the air mass metering system your vehicle would lose performance. If you can cram more air into a cylinder of a given size, you can get more power from the cylinder (in the same way that you would by increasing the size of the cylinder). Turbochargers and superchargers pressurize the incoming air to effectively cram more air into a cylinder.

Auto makers lobbied the government to make it mandatory for all vehicle operating on Canadian and US roads to be equipped with an ECM, O2 sensors and air mass metering systems so that they can control the fuel efficiency of their vehicles. They sold this electronic control system to the government as an emission control system. They said it would control the air fuel mixture ratio to lower carbon emissions. In reality it was set up to guarantee a greater demand for fuel and therefore fuel our dependency on oil. For decades we have been forced to buy vehicles that are very fuel inefficient. Just by changing the factory set air fuel mixture ratio we can be driving more fuel efficient vehicles, not by 2020, but as early as tomorrow.