higher fuel consumption without EGR?

Hi has anybody noticed this too? Recently blanked mine and fuel use has increased i tend to get about 20 to 30km less out of a tank on the motorway now

By theory removing EGR valve DO increase fuel consumption.

should make no difference, only there to lower emission's at idle and when off throttle by allowing a small amount of exhaust gas back into the inlet.

corsaZ22se said:

should make no difference, only there to lower emission's at idle and when off throttle by allowing a small amount of exhaust gas back into the inlet.

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I disagree. On z22se EGR valve doesn't open at idle or revving in neutral. That valve only opens when driving at about 1500rpm.

My consumption didn't change when I removed my EGR valve.

Johnss said:

I disagree. On z22se EGR valve doesn't open at idle or revving in neutral. That valve only opens when driving at about 1500rpm.

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Not sure how the EGR works on a z22se - but one thing i DO notice without it is the engiine revs more freely from 1500-3000rpm, so you may be right there. She is getting on a bit now with over half a million km 505,911 to be precise and it might just be mileage issue. Still no smoke out the rear and power is still fine tho

Engine gets to operating temp quicker with an egr, therefore it improves fuel consumption. Removing egr increases fuel consumption by approx 3%, the effect is higher when ambient temp is lower.

Project L850 said:

Engine gets to operating temp quicker with an egr, therefore it improves fuel consumption. Removing egr increases fuel consumption by approx 3%, the effect is higher when ambient temp is lower.

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That makes perfect sense and certainly mirrors my observations Lately my car is left outside so the effect is amplified i suppose!

I noticed my MPG drop when I blanked my EGR but only by a bit and more noticeable in the winter. From a little bit off digging and past experiences with heated and none heated inlet manifolds on old school minis the conclusion was that, yes you get a bigger bang with a cold inlet charge but you get better mpg with a warmer inlet charge.

i found my mpg stayed the same after 7years of not having one fitted with it fitted the intet would of been full of soot and the mpg degraded
i can confirm egr is only functional on cruising to make the fuel charge less when cruising for better mpg
that said the z22se will happily do 38mpg with out the egr on a run

For the same bhp, when inert exhaust gases are injected into the intake the throttle valve needs to be more open. This reduces pumping losses at part throttle (cruising), increasing mileage by a few percent.

Also the heat from the exhaust gases injected by the EGR enhances fuel evaporation, which helps after cold starts in winter (that's why our Z22SE throttle bodies don't have a hot coolant line going thru them).