6. The use of smaller words and shorter sentences 8. Their relationship towards the person which they are trying to persuade The EGR system routes a number of the exhaust gases (6 ? 10%) from the EGR valve, last on the Intake System, and ultimately within the combustion chamber. The exhaust gases are inert i.e. they cannot burn in the combustion chamber; also, the exhaust gases take up a number of the space which would preferably be taken with the intake air. This reduces the volume of intake air readily available for the combustion process during each Power Stroke; which in turn decreases the peak combustion temperatures. This brings about lower NOx emissions.