How's your mileage?

[MFenza]

mileage

I cant get over 10mpg around town or 15mpg on the highway I have a 373 rear mileage terrible Matt 3500 QC 4x4 dually Laramie

 

[catoiler]

I cant get over 10mpg around town or 15mpg on the highway I have a 373 rear mileage terrible Matt 3500 QC 4x4 dually Laramie

Yeh someone who tells the truth!!

 

[catoiler]

My milage has been pretty good. I have an 05 4x4 crew cab. TST. FASS 95gpm. Modified the stock air box and Banks charge air cooler and big head intake. If I run on level 1 or 2 @ 70 to 72 mph. I have seen as good as 25mpg avg. But it's usually right around 22mpg. When we got hit with the ultra low sulfur I had a 2mpg loss no matter what I did.

Are you reading those numbers off the overhead? If so you will be suprised when you figure it by hand. Also yours is a 5. 9 not a 6. 7.

 

[DieselLady]

I am not seeing it happen! Around town if you "drive it like you stole it" you are right there with me at about 10 mpg! the fwy mpg sounds close though. :{

Hey Mike, you are doing better than I am. I only get 13. 5 Hwy empty doing the had calculations and 10 to 11 around town. Soon to be working with the emission crap to see if we cant improve that.

 

[courierdog]

Milage 6.7

My truck earns its keep as a Hot Shot / Courier. 90% Highway miles at a nominal 60 MPH. No towing, carry less than 500 Lbs. Nominal 6,000 Miles/Mth

Prior to Rev A & B milage 17-22 MPG,

Post Rev A & B milage 16 - 21 MPG

Post Rev AU milage 15 - 20 MPG

Just had the DPF replaced under warranty, no significant change in milage but it does seem to run better no hard fuel evidence, yet, only made two trips of 300 miles each.

I love the comfort and drivability of the 6. 7 vs the 5. 9.

The 68RFE is a great transmission.

Requires an oil change every two weeks on average, 3000 miles the oil analysis says it requires it at this interval with my driving. I hope to improve this with a bypass oil filter as the soot contamination due to the EGR is excessive. In two weeks the throttle body has 1/8 inch of hard backed on soot.

 

[catoiler]

Hey Mike, you are doing better than I am. I only get 13. 5 Hwy empty doing the had calculations and 10 to 11 around town. Soon to be working with the emission crap to see if we cant improve that.

Betty, Was that you driving the 99 the other day at 35th and L-8 ??

 

[DieselLady]

Betty, Was that you driving the 99 the other day at 35th and L-8 ??

No that was a friend. She needed to borrow it to tow a trailer.

 

[DSpencer]

The difference between the first generation trucks and the new 6. 7 is night and day. You have a much heavier truck and the dual rear wheels are hurting you. The bigger engine is naturally going to get slightly less mpg's.



I have heard that the new trucks have a 3. 42 option and wonder what those guys are getting with the 6. 7 motor.

 

[BHolm]

My truck earns its keep as a Hot Shot / Courier. 90% Highway miles at a nominal 60 MPH. No towing, carry less than 500 Lbs. Nominal 6,000 Miles/Mth

Prior to Rev A & B milage 17-22 MPG,

Post Rev A & B milage 16 - 21 MPG

Post Rev AU milage 15 - 20 MPG

Just had the DPF replaced under warranty, no significant change in milage but it does seem to run better no hard fuel evidence, yet, only made two trips of 300 miles each.

I love the comfort and drivability of the 6. 7 vs the 5. 9.

The 68RFE is a great transmission.

Requires an oil change every two weeks on average, 3000 miles the oil analysis says it requires it at this interval with my driving. I hope to improve this with a bypass oil filter as the soot contamination due to the EGR is excessive. In two weeks the throttle body has 1/8 inch of hard backed on soot.

Wondering where the "throttle body" you speak of is located? Diesels don't have a throttle plate/body assembly, but I am curious as to where you are seeing baked on deposits?

 

[Powder Extreme]

Actually the new 6. 7 does have a throttle plate for the air intake. Sooting up that much in the short of time has me concerned, is this the "next" problem area we are facing? I installed a blank-out plate and some "wiring" into my '04. 5 Duramax to defeat the EGR, worked great and never had a problem in 50k+ miles.



Anyway, on to fuel mileage...

New truck before reflash 16mpg roughly 4,000 miles

After reflash 12 - 13 mpg

After recalled 02 module, 15mpg 10k miles



Needless to say I'm VERY disappointed I have done a considerable amount of heavy towing, the truck rarely sees a cold start (heated garage) NEVER sees short trips (usually 35 miles minimum) and is well taken care of. Yet I'm getting pretty poor fuel mileage and CONSTANTLY regen.



Can somebody please tell me the logic behind this?

300 mile trip towing 10k lbs, headwind most of the way, EGT never below 1,200 usually over 1,300. WHY IS THE STUPID TRUCK GOING INTO A REGEN MODE? What the heck is the regen going to accomplish? The EGT is already over 1,300.



Anyway, back to fuel mileage, LOL



04. 5 Duramax 3/4 ton crewcab 19-20 mpg

03 Duramax crewcab dually 18-19 mpg

01 Dodge ex cab dually 19-20mpg (heavily modified, 500hp at the wheels)

94 Dodge 3/4 ton 22-24mpg highest was 27mpg, yes a true real world 65mph empty 27mpg! Before you call me a liar, the truck was modified to about 375hp at the wheels and had an additional O/D behind the 5 speed. Overall final drive ratio put 85mph right at 2,000rpm. Which is only slightly taller than the final drive of my new "latest and greatest" Detroit offering.



IF every one of my trucks had the luxury of the tall final drive the new truck has, I'm certain the fuel mileage would be up at least 1-2mpg more. My 94 is evidence to that fact.



C'mon guys, seriously we should not be taking this crappy mileage laying down. All this new technology, tall final drive ratios, etc and 15mpg is the best we can do? The latest Duramax is getting 19mpg, (with slightly more hp/tq) no reason the 6. 7 shouldn't be.



Well, that's my $. 02 worth anyway :-laf

 

[catoiler]

I don't see how it is helping the emisssons when it uses twice as much fuel to do the same job! If the mileage was the same then I could see it but not as bad as these new trucks get!!

 

[Rdunkin]

Another fuel mileage update... . 16. 80 highway at 70-72mph at 7400' elevation.

This was with the Edge Juice on # 1.