Excellent MPG's w/EGR unplug = Cummins 6.7

[The Black Knight]

O.k. so a little over a month ago, I purchased a 2008 Dodge 3500 DRW(6.7 Cummins obviously) with the 6 speed auto. I was sad to see my 07 5.9 go, but I was having issues getting it re-financed and wanted a lower payment. So I ended up with a year newer truck with a considerably less payment.

Anyways, a buddy of mine has a 08 2500 6.7(that he purchased new), and he never has gotten the MPG's that I ever did with my 07 5.9L, which I figured was due to the DPF and all that BS.

So he unplugged his EGR and hence his MPG's when up, but he never equaled mine. So when I traded in my 07, I knew I wouldn't be getting great MPG's, and for the record, my best in the 07 5.9 City MPG's were 18 and highway 26. I normally ran between 15 and 17mpg's in the city and almost always a constant 25mpg's on the highway(and no I'm not making this up, it was all hand calculated). Also my 07, was modded with a home depot intake, amsoil filter, Diamond Eye cat-back, PUSHER intake and Hypertech Max Energy - set on Stage 2

Here's where the plot thickens. In my quest for exact mpg's from the 08, I've been driving it as much as I can, taking a few highway trips that lasted 4+ hours, etc etc.

My first initial fill up from the dealer netted me 11mpg!!! I figured I was screwed. I knew I would get bad mpg's but not this bad. So then, I went at it again. Another fill up and I got 13mpg. Improvement but not great(this is all city driving mind you).

So next, I ordered a MBRP muffler delete pipe. Did the Home Depot intake again, and installed another Amsoil nanofiber. With the combination of these three mods, I did a mix of City and Highway driving(where I took my long trips) and was netted with 17mpg's and then 16.5mpg's. Not bad a good improvement, but with a mix of highway and city, I figured it would be at least close to 20mpg's(I will say, that my City/Highway mix driving was probably a 70/30 mix). I thought I was at an impasse, until I finally caved in and DISCONNECTED the EGR...

My reason for not disconnecting, was I wanted to see what I could get by doing it the proper way(meaning EGR plugged in). I wanted to see how good I could really get the mpg's with everything plugged in.

So I broke down, unplugged the EGR, ran the truck all this past week and decided to fill up today(eventhough I had only traveled 110 miles). My main reason for filling up was I got to use a King Soopers card and get 10cents off a gallon(hey I take what I can get, especially when it's free). And I was curious as to what my MPG's would be, as I noticed the fuel gauge needle had hardly moved all week(only used an 1/8th of a tank, wasn't even close to 3/4's yet).

Well with 110 miles driven, I filled up with only 5.4 gallons... Yep a measly 5.4 gallons which netted me 20.3MPG's!!!

20.3 mpg's all CITY driving. All I did was go back and forth to work this past week, with some running around doing errands. 20 FREAKING MPG's in the city!!

To tell you the truth, when I saw this figure, I went from six o'clock to midnight in a heartbeat. I've never seen that high in the city, even with my 07 5.9 truck.

Lastly, I just got my Hypertech Max Energy today. Installed it on the truck and set it at Stage 2. We'll see how it affects the mpg's either + or - and I'll have to report back. Chances are, it won't make it go down, as I tend to drive very conservative even with the extra power on tap.

But even if it doesn't change for good or bad, I pretty sure I can live with 20mpg's in the city, I can't wait to see what happens on the highway.

[LordLosh]

And or Duh?
I have seen major problems running these newer engies with out the EGR plugged in how ever. I run a fleet of 20+ trucks, we had 6 newer 07-09 Ford diesel trucks EVERYONE i repeat EVERYONE i have had to take in multiple times to have EGR problems fixed. So i said fuck it and told my mechanic to unplug the damn thing. Couple weeks later i have all kinds of problems with the engine it blew a piston at 87,000 miles. So i warn you these new trucks do great with out the restriction of the EGR and sensors but they were not designed to run with out them. But Cummins is night and day to a powerstroke

[The Black Knight]

And or Duh?
I have seen major problems running these newer engies with out the EGR plugged in how ever. I run a fleet of 20+ trucks, we had 6 newer 07-09 Ford diesel trucks EVERYONE i repeat EVERYONE i have had to take in multiple times to have EGR problems fixed. So i said fuck it and told my mechanic to unplug the damn thing. Couple weeks later i have all kinds of problems with the engine it blew a piston at 87,000 miles. So i warn you these new trucks do great with out the restriction of the EGR and sensors but they were not designed to run with out them. But Cummins is night and day to a powerstroke
And that's why I was leery of unplugging it. But after reading tons and tons of stories of guys with 6.7 Cummins going 70k, 80k, 90k and over 100k with their EGR's unplugged I decided to pull the trigger and unplug. Even my friend with his 2500 08 has close to 40k and I'd say most of those miles are all EGR unplugged.

And yeah you're right, Cummins and Powerstroke are apples to oranges. You even look at a Powerstroke wrong and it starts having issues. As far as the Stroker tossing a piston, I'd say that's probably due to operator error more than the EGR. I work for the City and we've got tons of strokers running around. Biggest issue I've seen with these trucks when they have problems is I've noticed how people treat them. Zero warm up times, zero cool down times, etc. etc. I mean guys drive these trucks hard and don't care about the issues because it isn't their personal truck. So they beat on them hard.

As much as I like to pile on the Powerstrokes, the only real issue's I've seen with them are cold starting problems, de-fueling/priming problems and getting anti-freeze into the fuel.

I was riding with a guy in a F550 dump bed truck(which weighed 12,500 empty), we had a load of dirt, pulling a long tandem trailer with a big ass CAT skid on it and attachments. Going up a 10% grade hill easy and the truck could barely do 30mph. He had his foot in it the whole way up the hill. It was hurtin big time but he didn't care. Not his personal vehicle so he floored it the whole time. When we finally got to the top of the hill, the air conditioning just shut off. That's how taxed that motor was. The AC didn't work until later in the day, when the truck had a chance to cool down.

So yeah, I think guys are beating on these trucks, and if you've got a fleet of 20+, There's bound to be someone treating the trucks poorly, especially if it's like the City, where everyone drives everyone's vehicle. No one is going to treat these trucks like it's their own.


P.S.
The EGR has to do with the DPF, so I don't see how it could have been the symptom for throwing a piston. EGR just helps the truck do more re-gens because of the DPF. In all actuality the EGR unplugged, will allow the truck to not go through as many re-gens. Yeah the DPF may fill up more, but as soon as the EGT's get hot enough, it'll just burn it and blow it out the tailpipe.

[LordLosh]

All i was saying is the designed these new engines around the egr system to pass all the emission bull shit, so in theory things may or may not work better down the road long term with out the EGR plugged in, and you didnt say how many miles were on your truck or if you even had warranty but if you do they can tell if it has been un plugged so.. its a gamble

[The Black Knight]

I'm over my 100k Cummins warranty, so yeah if I needed to work on it, I wouldn't take it to the dealer. Plus I've got my Hypertech, that can switch the truck back to stock mapping and turn off any CEL's, once the EGR would be plugged back in. I'm sure they could tell something is up, since they go off of how many key starts since last flashing, so they would know it's been altered, just not by what.

[Tylar]

I have a 2004 PSD that has 111k and is bone stock. If I ever have a need to do something about the EGR, I'd not delete it....just replace it with an aftermarket redesign. I think we can all agree that when Navistar designed the EGR in the 2004.....they hired a physics flunkie to do it.

[The Black Knight]

I have a 2004 PSD that has 111k and is bone stock. If I ever have a need to do something about the EGR, I'd not delete it....just replace it with an aftermarket redesign. I think we can all agree that when Navistar designed the EGR in the 2004.....they hired a physics flunkie to do it.
I think that's why alot of the Cummins guys just unplug it. That way if you need to turn it back on, it's only a reconnection of the plug. I know alot of guys are doing full on DPF and EGR deletes, which I think is great because once the DPF is gone, there is no need for the EGR. Which if you can get rid of those components it would make the 6.7 run like the 5.9 Cummins.

The only issue with that is, for guys like myself that live within City Limits. We are required to do emissions testing. Now if I lived in the rural part of the county(El Paso), where Emissions is not required, then I'd go all out and junk all of the emissions garbage.

I don't know how it works in other counties, but for El Paso, that's always been the nice thing in that if you live in the county you're not required to do emissions. And it is a nice thing to have, as I have first hand experience. Back in highschool, I had a 1976 F150, with a 1970 302 motor in it. Well in 1970 that particular motor didn't come with emissions, but the 1976 F150 truck did. So the way I got around the emissions testing was I just registered the truck with a friend out in the county and never had to deal with emissions ever again for that truck.