Considering the previous, EGR is expected to have a
negative effect on engine efficiency. This is verified
observing Fig. 3 providing the comparison of calculated
and measured values for engine brake thermal efficiency as
function of EGR rate for 1130 and 1420 rpm engine speed
at 100% load. The calculated values are close to the
experimental ones and most important the simulation
predicts the qualitative effect of EGR rate on brake
efficiency for both engine speeds examined. Obviously the
use of EGR has a negative effect on engine efficiency that
increases with its percentage almost linearly. This effect is
more pronounced at low engine speed.