EGR is great tool for warming up engine but once is engine at operational temperature EGR does more damage than help.
In reality THERE IS NO MAGIC just COMPROMISE and very few understand big picture and what every little change causes.
Dynamics of Mother Nature
- energy = heat = power = heat
- already burnt wood doesn’t burn again – we all know that yet EGR allows recirculation of burnt or partially burnt fuel back inside your engine. It is like eating shit and believe you can live long and healthy.
- fire doesn’t burn without oxygen – we all know that yet EGR reduces oxygen levels in combustion chamber. Gases in atmosphere contain about 21% of oxygen. Try run with gas mask, see how quick you are. Or better yet put t-shirt over your mouth and nose…see what happen when you run.
Technical facts and compromises
- EGR is fully closed at full load/WOT or high loads (60-100%)
- EGR reduces NOx emissions at partial load (<60%)
- EGR increases HC emissions at partial load
- EGR increases CO emissions at partial load
- EGR increases soot and particles at partial load
- EGR is thus effective only with DPF
- EGR reduces life of DPF (price 700€ for my car)
- EGR increases carbon deposits at partial load
- EGR increases fuel consumption
- EGR reduce thermal efficiency and thus power output of engine
- exhaust gases leak around piston rings and contaminates engine oil
- dirty engine oil wears down engine quicker – with EGR on, oil intervals 5000km. Forget about long life engine oil propaganda. More info about proper engine oil changes.
The Magic of Science
Why the hell would manufacturers create such a complicated system if it doesn’t work? Imagine there are people who believe black thick smoke from exhaust create more power and there are even more people who believe there are free lunches…read powerful cars with little or no energy consumption.
All you need to do is to sponsor some academics who create theoretical study with fancy graphs. It looks great on paper but nobody really understands what all those graphs and values means. It reads reduce emission, increase power, reduce fuel consumption.
It is as simple as that. I’ve seen many studies regarding EGR. All of them were full of confusing results usually contradicting each other. But all of them didn’t account for reduced power and increased fuel consumption.
In other words, to keep same power we have to press accelerator harder to get same engine output. Who really knows how your car suppose to really drive. It is vicious cycle with long term damage and ecological catastrophe.
Little or NO REAL BENEFITS
In the end, there is very little real benefit in reduced emissions if one compensates for loss of power. To get more power, you need more fuel and thats what they somehow forget to tell you about.
One wonders what is point of reducing emissions if you have to use more fuel just to produce more emissions in order to keep same power output.
But EGR is great tool for warming up engine but once is engine at operational temperature EGR does more damage than help.
As you can see from images that’s how looks like typical EGR after about 220,000km on ODO. And that is on relatively high quality diesel fuels from Germany and Austria. I saw more scary things on third world fuels in Czech Republic.