corsaZ22se said:
that's what idle control is for! egr will open at idle once engine is at normal temp and after being on power.
any gain in mpg is minimal as the egr is for lowering emissions
most if not all new engines burn more fuel in order to lower emissions by making a cleaner burn and in some cases by injecting fuel in to the exhaust before the dpf/cat.
if egr was to lower mpg then manufactures would have taken a hot air feed from outside of the exhaust manifold so as to introduce clean hot air to the inlet rather than dirty air from the exhaust system via a valve that will soot up and stick/fail at some point.
its just what i read on a vauxhall document about egr systems ""the car would have better mpg with hotter iat""
and as said on the post you disagreed with these cars are just as efficient without the egr ive proved that over the last 8 years by not having one 🙂
the sai system was also for emissions
""In internal combustion engines, exhaust gas recirculation (EGR) is a nitrogen oxide (NOx) emissions reduction technique used in petrol and diesel engines. EGR works by recirculating a portion of an engine's exhaust gas back to the engine cylinders. Exhaust gas is routed back into the combustion chamber because the exhausted air is much hotter than the intake air. By sending warmer gas into the combustion chamber, the air/fuel mix does not have to do as much work to heat up, and your engine runs more efficiently.""
