This figure shows the variation of specific fuel consumption with percentage of EGR. Specific fuel consumption increases with increase in percentage of EGR for the same speed and load. When EGR is applied, less amount of fresh air enters into the cylinder. But amount of fuel remains almost the same. As a result the combustion takes place at a rich F/A ratio than that without EGR. Thus specific fuel consumption decreases with increase in percentage of EGR.