[mwebb]

Originally Posted by Old Mechanic

mwebb;

If I introduce more of any type of gas into an engine the compression pressure created by the stroke of the piston will increase.

The type of gas is irrelevant.

The volume, density, and temperature are relevant.....
regards
Mech

this is your error

the volume of gas in the combustion chamber does not increase with introduction of EGR
the total volume of gas remains the same only now
some of it is INert EGR gases that can not support combustion
the rest is the same mix of air fuel that was present without EGR

so
peak combustion temperature is reduced
peak combustion pressure is reduced
NOX formation is reduced

these are the facts.
i intend to take one INcorrect concept at a time
(regarding EGR) and refute it .
focus , on this fact , provide evidence to prove me wrong
if you can.

when you can not , we will proceed to the next concept
========================
understand
there is no bad side to EGR , only good .
when the system is functioning as designed , FE is enhanced and pollution is reduced . another fact .

i can explain the HOW and WHY EGR may cause problems on some systems but first i need to be clear on theory