First post!!!!

I just picked up an 07.5 Megacab with 4k miles on it, been driving it around locally for a week and then this week took it on a 1800 miles trip. The trip out I averaged 10.5-11mpg with cruise set on 70 most of the time (until I hit the ice). That was 3 fill ups hand calculated and it jived with the OHC most of the time. I didn't like that, go on here and did some reading and it seemed my best bet for a quick couple mpg's would be to unplug the EGR, did that and came home and the mpg's was about identical to the trip out and the truck ran the same.

I've now got 6600 miles on it, all I've done to it is changed the oil and I see a couple stickers under the hood where it's been updated. Is this common? I was hoping for high teens with this thing???? I came from a 7.3 Powerstroke, this is a completely different animal but I was honestly expecting better mpg's.

Thanks!

 

You'll need to put some good hard miles on that motor to get it broken in, then the mileage will come. That and losing the dpf and muffler... accidents happen...

 

You probably need to pull the butterfly flap out of the intake. Chances are that it is partially closing while you are driving and that may be keeping you from getting the mileage gain...

 

Butterfly flap?? Pre or post air filter? Haven't even taken that out yet to see what it looks like.....

 

It's in the metal box type thing on the end of the intake manifold on the driver's side right under the EGR plug. The intercooler boot connects to it. It has Siemens / VDO molded into it....

 

K. Thanks. I'll look for it.

Today I got the surging in reverse and off idle, I assume that's the problem that I heard about could occur as a result of unplugging the EGR, but I thought that would come about right away?? I've had it unplugged for about 1000 miles now and today was the first time I had any surging.

 

take it back in to the dealer and get the latest flashes. tell them the milage is horrible and you have a bad cold idle and they should update the ECM to the newest flash. That may help the idle with the EGR unhooked.

I have heard that the new flashes improved the fuel milage quite a bit

Chris

 

I had it in last week to get the high idle control turned on, cost me $45!!!

They said it had all the available updates done, but I don't have a lot of confidence in that place, they couldn't even tell me how to use the high idle.

Went 180 miles yesterday, pulling an empty 24' low profile enclosed trailer and say 9mpg the whole trip. My powerstroke would have got 16 easy and 13 if the trailer was loaded down. NOT AT ALL HAPPY WITH THIS THING!!!!

 

when i first got my truck, a 3500 mega. i averaged between 14-23 empty, with variable conditions. the 23mpg was during a trip of almost 500 miles of coming down hill. rockies to coast. first tow netted me 8.5 for 1300 miles. i'm up to 19,000 miles. now i'm averaging 14 city and 18-24 highway. and 10.5-11 towing. doesn't matter if the 26' car hauler is loaded or not. when loaded both the hauler or the r.v. are around 11,000 lbs.

i'm actually getting better mileage than a friends 2nd gen 4x4. but not as good as another's friends 2nd gen 2x4. both of them are 2500's.

this last oil change, i switched to a synthetic blend. i will put on at least anouther 10,000 miles before swithing to full syn.

no engine mods. only a msd status monitor, to read trans, oil, turbo, ect. instead of installing guages.