Quote Originally Posted by squeaks130 View Post
I may be wrong, but in the past I have heard that the egr is used to lower combustion temperatures. And one of my professors said he has seen blown engines cause it was running hotter, due to the egr being disabled.
yes and no.

it lowers combustion temperatures because it is taking up excess space in the combustion chamber since its inert. the only time the EGR is active is during cruise, so there is absolutely no way that someone blew up their motor because they disabled the EGR.