nonnieselman

iTrader: (10)

I can get 21-22mpg out of my truck.. but in town drivin it pretty rough keeping the rpms about 2000 i get about 15 or so.. on the interstate ive gotten 21 a few times and 22 every now and again..

Im still not through tuning it though, dont have DFCO or anything like that Enabled.

But i have 275/60/16 tires... 29" Tall and 11" Wide with 3.42 gears, Speedo calibrated with GPS.. 70mph is 2000 rpms exactly.
Ive thought about goin with a 30 or a 31" tire but most of my driving is in town and country roads. so i cruise at about 55mph most of the time..


My buddy at work has a CCSB 1500hd 4x4 6.0 and he gets a best of 14 on the interstate...

motion427

iTrader: (1)

I did one a while back w/3.73 gears and 245 tires.I tuned the VE.But when I activated the MAF,it was spark knocking like crazy.
It was doing it before,but not as bad.That why he ask me to have a look at it.
The maf was off by 8%-10%+ everywhere at 35%+ throttle.
After we set the maf and the PE,It ran completely different,a lot better(could not have been worse for sure).He hauls a 28-30ft trailer.He said he got 12mpg with the trailer.I don't remember him saying anything about MPG when he's empty.Don't know if you looked at the MAF allready.If not,have a look.
Good luck

Snake Eater

I just ran a whole can of seafoam through the pcv. It would idle down to 250 rpms when I let it suck in too much at once and would quickly jump to 3,000rpms and idle there for a minute. I got down to the last 8 ounces or so and just stuck the tube to the bottom of the cup trying to kill it. It took maybe 2 seconds to suck in the entire cup till nothing was left and it didnt even stumble. lol Anyway, i killed it and let it soak 12 miutes. It fired right back up and only had a very slight haze out the tail pipe for maybe one minute. It did idle rough the first couple minutes but cleared up. I tried some full throttle launches and DAMN, for the first time it jumped sideways spinning both tires about 5 feet and went to one tire for another 10 feet. It has never spun the tires before, even with the stock tiny 245's. I am in Brownsville right now so no open streets to get some speed up, but 0-50mph I didnt hear a bit of knock. I may be here a couple more weeks so I wont know if the milage is up any till my drive back to Houston.


I really am impressed with the results but I sure thought the exhaust would smoke more than it did. Maybe it wasnt all that dirty.

shandy294

Those are some dramatic results from just Sea Foaming the intake! I just did mine 5 days ago with about 1/2 can and it didn't even smoke that I could see. I didn't kill and soak the engine though. I ran a can through the tank a few weeks ago and didn't notice any difference from either procedure. I guess it didn't need it.

I know a guy who has a 03 SSS and it gets 13mpg all the time. I don't know what his gearing is.

My mild-mannered truck gets about 21 hwy on cruise at just under 2k rpm.

yurs78

I have an '03 1500HD CC with the quadsteer. So the set up should be almost exact. First of all I don't think that the truck only weighs 5600 lbs. I think it's around 6400 or a little more (that's what mine was on the scales). So there is a lot more weight there than you'd think. My truck was crap for milage too when I got it. I got a the 89 octane tune from nelson and that helped a lot. At the speeds you're talking about I'm at 14-15 mpg, and I've never heard better from a truck that big and the 4.10's. I had a '99 2500 regular cab with the same drivetrain and 3.73's and that did average a lot better milage than this CC. The weight and the gears really hurt it.

Jeanyus

My 06 1500 HD 6.0 with 4.10's. Gets 14 MPG city and 16 MPG at 70 MPH highway. When I hook the 22 foot 5600 lb camping trailer to it I get 11 mpg.

SS Crew

I had an 04 2500 non HD ( same as 1500 HD) Quadrasteer with the 6.0 and 3.73 gears. I got between 12 and 13.5 on the highway running about 75 - 80 mph. After I got a 91 Hot Tune from Westers my mileage on the highway went up to 14.5. I got popped speeding and did the remainder of the trip not exceeding 70 and pulled almost 16 mpg.

It seems that if you keep the rpms down it really makes a difference. I had an 99 with a 5.3 and running at about 80 mph I could still pull 17+ mpg. The 6.0's are just plain ol' gas pigs.

Toonz

iTrader: (6)

You guys have me wondering how bad my new Sierra Denali will be, it has the 6.0L and AWD. Not sure on the gears though since I haven't picked it up from the dealer yet.

TURBHOE

iTrader: (4)

what year? the new ones have the 6spd don't they?

Toonz

iTrader: (6)

It's an '06 but only has the 4 speed. Maybe a tranny swap should be the first mod on the list... have to wait and see.

Just found this quote online:

"The Denali is fitted with a 345-hp, 6.0-liter V-8, while the 1500HD is powered by a 300-hp, 6.0-liter V-8."

Wonder if that will make a difference...