Quote:
Originally Posted by COcyclist
I can add some personal experience to fuel this debate, at least as far as the VW diesel is concerned. I installed this tune Dynamic EGR Control for TDIs - TDIClub Forums from Malone tuning about two years ago. I also put in a hierarchy temperature Stant thermostat and my highway mpg has gone up about 10% . Click on my fuel log.
Everything I read says that diesels like to be fully warmed up and be supplied with lots of clean, cold air. EGR is hot and dirty and has less oxygen. EGR hurst fuel economy in a diesel. |
Hello Cocyclist. You wrote the title of my answer. I agree in general on yr opinion. But would like to have facts to sustain it. Did you make a test with a trip computer installed and on the same tract of road, keeping all conditions "ceteris paribus" but EGR? That is the only valid way. Otherwise it is just a suspition based on a (biased) opinion.
In my car I did the same and the effect was opposite. See my fuel log. I wanted to improve FE, disconnected EGR and FE went worse. There are documented reasons for that. Then I reconnect it back, and FE improved.
One cannot rely on fuel tanks FE to get a valid conclusion. From one tank to another, in 700 km travel, many things may change, such as temperature which affect tires, air density and resistance, road surface which is very important, load (passangers and baggage), slope, traffic, extension of continuous driving (it is not the same to drive 700 km in 7 tracts of 100 km each compared to drive 700 km in 40 tracts of 17,5 km), altitude, to mention a few factors that affect FE. Not to mention driving strategies, which may have a 40% effect. And when you want one thesis to win over the other, conciously or unconciously you can make one to be the champion.
Cooler air input makes sense to me, though. What I wish do is to install a trip computer in my car for testing all this mods properly. After that, I will try to install a EGR air cooler, and see what happen, measuring with the trip computer. Compare FE with and without EGR, etc. Explore and test all combinations.
My plan is to use MPGuino, which I already got, for which I am waiting for a mechanic friend of mine who will come to help me.
Regards,
Oldbeaver