what are you guys getting for mpg?

[grayharville]

I get 15.5 in a 2010 ccsb z71 5.3 6 speed 3.08 gears, straight pipe exhaust and 10 ply mudgrips.

My mom has an 07 Tahoe that she escorts with and gets about 20 following oversize loads.

My 70 gets roughly 10 and my 4x4 gets 8
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[piecesparts]

Originally Posted by cadpwrd

Last weekend I took a trip to Canton, OH (with a pitstop at Summit Racing in Tallmadge). It was about a 3 hour drive from where I live in western NY. My 2wd RCSB with the 4.3 averaged 19.6mpg with the cruise set at 73mph. That's the best Ive seen on the highway. I usually average 13/14 mpg around town and 17/18 on the highway.

I have been getting 18.6 daily going back and forth to work, with the 5.3 in my 2011 GMC, in the cold weather. It has not been that cold around Kansas, this year, but the mornings at 4 AM are usually around the high 20s. This is with the cruise on and the bed cover open. I have found that the colder weather, below 45 degrees hits the mileage harder on this truck.

[dishow]

Well, I've had my truck a little over a year now,and I am cosistantly getting 15.5mpg.
I'll take that over the 13.5 at the breakin point. hahaha.

but its sooooooooooooooooooo nice. still LOVE IT!

[piecesparts]

Originally Posted by dishow

Well, I've had my truck a little over a year now,and I am cosistantly getting 15.5mpg.
I'll take that over the 13.5 at the breakin point. hahaha.

but its sooooooooooooooooooo nice. still LOVE IT!

My guess is that your mileage could be associated with the 4X4 in your truck and the fact that you drive in the city a lot. My 2011 gets average at 18.5 (mixed driving) and if I keep the speeds at 70 or less, the mileage climbs above 20. I have even been playing with my trips to work and if I stay out of cruise and work the gas pedal to stay in V4 mode, the mileage goes to 2. It can be done, but I would not like the truck very much if I had to do it all of the time. The items that I did to the engine air intake, exhaust and tune were done to enhance my performance.

Remember, I am running a 3.42 gear and 265/50/20 tires on this truck. The whole thing is in what the RPMs run and the efforts that is involved in making the engine work the best at an optimum speed.

[dishow]

yeh, i have the 3.08 gears with 275/55-20 tires. if i was to have ordered it,id had got 3.42.,but i took the one they had on the lot that had everything else i wanted. overall, after a year of ownership, I have no regrets trading the 2010 camaro in for it.

[piecesparts]

Mine came with the 275/55/20 tires and I traded them off for a little shorter tire to get more wheel well clearance, when I lowered it. I like the tires that I am now running and the slight change in the gear ratio was not a bad thing either.

[72BlckButy]

15 day in and day out...

'08 4x4 CCSB 5.3 3:73 gear... Towing around 10-11.

[Richardman1992]

I get about 18-20 mixed driving with cruise and no ac(I never run it) with 285/75r16's and a black bear tune. I wonder how much it'll go down with the cam,stall and efans
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[FLDBRED]

As of 6/15 my son has owned his truck for a year. It gets an average of 15.6 MPG. It is 1500, 6.2, 4x4,auto, 3.73 g80 rear. It has none of the active fuel management garbage and he drives it real hard. If he baby's it on the hi-way he can get 20 mpg. We thought long and hard between the 5.3 and the 6.2, we chose the 6.2 because it didn't have the AFM. He's VERY happy with this truck!

[old_blue_truck]

I picked up a 2012 Z71 Extended cab, 5.3 with 3:42 gears a few weeks ago. I have been avging about 16.5 with a high of 18.3. We previously had a 06 with the 4.8 and it drank fuel. It just wasn't enough motor for the hills around here. Pretty happy with the mpg I am getting. I didn't buy it for the fuel economy lol.

[BuildinA68]

I know the mileage or fuel economy reading on the dash isn't very accurate but my 2011 Sierra with 6.2 - 3.42 - 4x4/z71 says 16.8 with mixed driving. I reset it to see if I gain any mpg's with the diablo tuner. Probably not but the tuner really woke the 6.2 up all across the board. K&N filter, no cold air or exhaust mods
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[nobolt]

you guys are scaring me. i'm thinking of getting a '13 extended cab, 5.3 to replace my '05 EC 5.3.
i have gotten as high as 20.3mpg in summer...reset every tankfull. usually 17 in winter. no hwy speeds 50 mph and under mostly. everything is 2 lane blacktop, flat and no stop and go.
i think i better test drive a new truck and watch the computer. my '05 computer is accurate, BTW.

[OLDIRON69]

My '05 2500HD gets 8 at best towing a 24' enclosed trailer. If I drive right..which hardly ever happens I get 15 on the hwy empty. I'm a tree broker and haul alot of heavy loads. I really need the D-max but the 6.0 gets it done. Water pump just replaced two weeks ago, believe it or not it was putting so much drag on the motor for the last 2000 miles it had the power steering pump sounding like a cat in a vise..I think the mileage is even improved 1-3..still keeping an eye on fuel to see but I know it was killing the mileage even more.

[pmkrew]

My DD is an '07 suburban 2500 6.0l 4x4 and 3.73's (I think) and I get around 12 city and 16 hwy (avg speed of 80).
After reading this thread I am not quite as disappointed in the mileage it gets but would like it to be better...
Any suggestions that have netted you actual performance and economy results?
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[Andy4639]

I have a 08 Tahoe 4x4 with 65,000 on it. It had 28,000 when I got it. The best it's ever done was 19 and I babied it the whole time never running over 70MPH on a 300 mile trip. The speed limit was 65 for the most part.
The gas milage sucks on the newer vehicles. The e-85 isn't worth the extra pennies either. I will never run it as long as regular gas is with in a $1.00 of it.

[Dale99]

08 sierra 4x4, 5.3l, 3.73 axle, 4l60e trans.

averaged 16 on a road trip. Speeds between 55-75.

[Matt Man]

2009 gmc sierra with 305-55-20 bfg all terrains 33.4" tall gets 15.8mpg average.
Im going to upgrade the gears to 3.73's i currently have 3.08...

[Low87]

First week or so in the '08 (5.3 Z71, no idea on gears, CCSB, factory rims/tire size) was a mix of city, highway, plus city/highway with a loaded trailer, I got 14.8. Memorial weekend was mostly highway at 80mph with some city, got 16.1. This week normal city/highway no load I'm getting 15.8.

[72BlckButy]

15 for me on my '08 CCSB 5.3 w/ 3.73's, Z71 4x4.

On a trip to NJ I drove 75 MPH there and back w/ a 2,000 lbs steel deck trailer; on the way back I had an additional 2-3,000 lbs. On the way out I averaged 18-19 MPG and on the way back loaded I average 15 MPG. Overall the trip ranged from 16.5-17 MPG at 75 MPH. Not bad in my opinion.

[Dalaigh]

Did some calculations yesterday, and with the 3.5" lift and 285's I'm getting 16mpg combined. I was getting 17.5 before, the only engine upgrades are a cat back and Airraid Jr intake and dry filter.

[BuildinA68]

Installed a heartthrob single exhaust and k&n cold air kit, and dyno tuned. Got 330hp to the wheels and 355 ft lbs torque. Mileage didn't change to much from my earlier post. Dash still reading 16.5. Big difference after the dyno man played with it. Will chirp third when on it!! 2011 GMC Sierra ext cab z71, 3.42 gears.
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[nobolt]

just looked at both trucks:
2005 ECSB 4x4 5.3 leveled in front 3.07 rear end - 18.9 mpg over the last 800+ miles
2013 ECSB 4x4 5.3 (10 days old) 3.46 rear end - 20.5 mpg 148 miles

you will know how i get these mpg numbers if you ever get to follow me. the '05 has a sweet spot at about 48-49mph (speed limit around here is 45mph)