Your 6.0 mileage

12-13 around town .. 14-15 highway - 04 CCSB 2500HD 6.0 4.10s 4L80E

Last tank I got 9.5....issed: 04 2500HD 6.0L 4L80E 5.13 38" Tires

hmm 2005 2500hd 6.0 4.10s on 285s with intake and fairly light pedal......... never got over 11mpg

sounds about right, what size tires do you have?

my 2001 2500HD 6.0 4x4 4l80e 4.10s on 285 BFG mud terrains, custom pcm tune, k&n and exhaust,
i would average 15-16mpg driving around home (open country roads, averaging 55-60mph, mostly 30mi trips to and from town/gf house),
then 11 mpg when driving around school here in Raleigh,
13-14 on the interstate (averaging 75-80mph, would have done better if i drove a little slower, those 4.10s dont like the highway) and
about 10-12 pulling goosenecks

so your 12.5-13.5 sounds about right if you drive in town alot and highway

oh and first tank with the 37s and still 4.10s i got 12, and then 8 pulling my boat, this was not corrected for tire size, the other numbers were as my PCM was calibrated for the 285s

Sounds about the same as mine. Did you get rid of the 98?

Mauro said:

My DIC says 14.4!!! :rofl2: :rofl2:

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Lies!! :anitoof:

I get 13.5 in mine at 85 mph with the a/c blowing hard. But she burns oil.

i thought tunes really helped the 6.0's economy... but i guess if only if youre rolling stock tires?

Im on stock tires and getting 15+ out of mine. Part throttle tune is a big help to fuel economy. I tune with HPtuners. When I first got the motor it got 12 if I was lucky.

6 inch lift 35" BFGs and im getting 11-14 depending on where i drive. and this is hand calculated. but what the hell, we all bought trucks because we love them and what they can do. not their gas milage

Anthony said:

i thought tunes really helped the 6.0's economy... but i guess if only if youre rolling stock tires?

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Mine did ok when I had 285's on it. I would get anywhere from 13.5-14.5 in town and I got a best a 16.5 all highway once. I think I can get 15-15.5 in town now if im light on the skinny pedal. I havent done highway yet with the smalller tires though.

Anthony said:

i thought tunes really helped the 6.0's economy... but i guess if only if youre rolling stock tires?

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When you go over 2200 rpm in a 6.0 your economy goes down hill. I thought 13.5 at 85mph in a 1 ton truck was pretty good. I get about 16-17 at 70 mph.

01 1500HD 3.73s & 315s and i get 12mpg city WITH a black bear tune. The tune didnt help me any, but good power.

Todd said:

When you go over 2200 rpm in a 6.0 your economy goes down hill. I thought 13.5 at 85mph in a 1 ton truck was pretty good. I get about 16-17 at 70 mph.

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I figured if I was willing to drive a little slower I would see quite an improvement.

As for tire size 235-85-r16, when they wear out I am stepping up to 285-75-r16 if I can fit them. It came stock with 245-75-r16 and I have reprogrammed the spedo for the 235-85s.

And I'm not complaining about mileage, just curious how it sits with the average. I would like to see 14-15, but it looks like I will have to slow down if I want that.

I got 12 driving 80 to fresno today
look at this page
http://www.gmfullsize.com/forum/showthread.php?t=78159

I forgot to mention that I get 11.5 on trips.....although my speedo and mileage are off right now, I need to get my tire size changed, but my tuner moved away!! :bawl:

Mine gets such bad mileage that I'm thinking of selling it and getting an old Ford Escort or maybe even a Yugo. Then after that I'm gonna shoot myself in the head while hanging from a long rope.

That or I'll just say FU## IT and enjoy the hell out of my truck while ignoring the piss-poor mileage and huge carbon footprint I must have!!!! :rocking: :anitoof: