Chevy and GMC Duramax Diesel Forum banner
  • Hey Everyone! Enter your ride HERE to be a part of this months Ride of the Month Challenge!

1 - 9 of 9 Posts

·
Registered
Joined
·
222 Posts
Discussion Starter · #1 ·
So i just took a trip from Scottsbluff,Ne to Powell,
Keep in mind that my lmm is completly stock no delets or anything. Im running 265/75-16 tires, And 3.73 gears. Im completly aware that if i do delets and a decent tune that it would change things alot!! I was just very surprised at what I seen.
I hand calculated going up and all I could get out of it driving mostly the speed limit was 13-14...coming back which is down hill I got about 16-17 was all. I have some friends around here that have very similar pickups and they seem to do much better than I. Im just wondering if im missing something or if thats about what I shoud expect. This was all with the same grade fuel and conditioner. I understand this is a big pickup and shouldnt expect 35mpg out of it or anything but I really thought it would do a little better
 

·
Registered
Joined
·
4,629 Posts
Also you would be surprised what a dirty FF & or Air Filter will do to mileage...
 

·
Registered
Joined
·
222 Posts
Discussion Starter · #4 ·
well i should have added that i just had it serviced not to long ago and had them put in new AF and FF maybe I just need to change them myself and that way I know. I liked having GM do it so that everything was documented but maybe im just going to have to go back to doing everything myself...


I have no idea about regen????? I have never seen it say its going onto regen or not???
that was going to be my next question is how do i tell if it regens???
 

·
Registered
Joined
·
16,262 Posts
I have no idea about regen????? I have never seen it say its going onto regen or not???
that was going to be my next question is how do i tell if it regens???
You wont get a msg saying youre in regen. Only msg you could get is a DIC msg "CLEAN EXHAUST FILTER." If you get this msg its because the truck in not being operated in a manner that allows affective DPF cleaning. If this msg comes on, drive it above 30mph untill the msg clears.

Regen happs once per tank full. I can tell its in regen by noticing, RPM is slightly elevated (@ idle) mpg drops, oil life % drops, engine sound (@ idle) & a raw diesel exhaust smell.
 

·
Registered
Joined
·
3 Posts
I've only had this truck 1 week. Went on a short trip and from a cold start average milage kept climbing up to 19.5 mpg. This is on interstate with cruse set at 65.

When I got onto a local hwy the average dropped as I went through town. On the other side I set the cruse at 60 and watched the average MPG. At 16.6 mpg it started going Down until it reached 16.0 mpg. I was really scratching my head at that until reading this thread and realizing it was probably Regen kicking in.
 

·
Premium Member
Joined
·
404 Posts
Yep, and unless regen runs it's complete cycle, it will keep starting over everytime you start the truck until it is able to finish...

That makes the MPG's drop like you have a hole in your tank....
 

·
Registered
Joined
·
222 Posts
Discussion Starter · #9 ·
well thanks guys...sorry I havent been on for a while I started a new job and dont have as much internet access...my tires are 265-75/16 running 50psi in them no bed cover and yes there was wind through out the trip some places yes and some no kind of evened out...
I have never gotten the message "clean exhaust filter" so I think im ok there...this pickup is mainly used to pull trailers I dont usually DD it but there are some instances...I will probably have to go in and have it serviced all up again...maybe I going to have to put a real mild tune on it for a bit and see what happens....EFI...here i come lol
 
1 - 9 of 9 Posts
Top