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Old 02-27-2013, 10:25 PM   #1 (permalink)
PEANUTGRWR
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fuel mileage help

I have an 08 lmm that gets terrible fuel mileage. It has a ppe hot+2 tuner on it with the cat, muffler and particulate filter all taken off. its a 4x4 crew cab short bed. on a good day it might get 15 mpg if im lucky at 70-75 mphany ideas or suggestions to improve this? it doesnt seem to matter what setting on the ppe I use, they all suck as far as mileage. I sure wish I had my old lbz back. is there any easy way to make this a lbz with just a ecm chance lol
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Old 02-27-2013, 10:41 PM   #2 (permalink)
chevyinlinesix
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An LBZ is basically an LMM without the extra emissions equipment. How old is your air filter? It's an easy part to forget about.

Which method are you using to calculate your fuel mileage? What brand and size of tires do you run, and at what pressures? If you have gauges, how much boost do you typically run when you accelerate and when you cruise?
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Old 02-27-2013, 10:44 PM   #3 (permalink)
PEANUTGRWR
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filter is recently new, napa gold brand. the display is within a half mile of doing it the old fashion way. run 50 lbs in the tires 265's and I dont have a clue on the boost i rarely look at the gauge

speedo is corrected for the tires
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Yea, though i drive through the valley of powerstrokes,
I shall fear no blown head gasket:
for dependabilty art with me;
Thy aluminum head and Thy power, they comfort me.
Thou hast anointed my bearings with oil;
My pickup overpowers.
Surely traction and victory shall follow me
All the days of my life;
And i shall dwell in the house of the DURAMAX forever!!

Last edited by PEANUTGRWR; 02-27-2013 at 10:45 PM.
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Old 02-28-2013, 12:45 AM   #4 (permalink)
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Are the tires an aggressive tread? When was the last time you changed the fuel filter? Put some more air in your tires. Also try a different brand of fuel. Like Chevron/Texaco, ConocoPhillips, Mobil, etc...
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Old 02-28-2013, 04:59 PM   #5 (permalink)
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for what it's worth, I've read non OEM tires that are wider can significantly reduce your mileage..............
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Old 02-28-2013, 06:12 PM   #6 (permalink)
Jaybeecon
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15 MPG at 70 to 75 MPH is pretty damn good!
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Old 02-28-2013, 06:14 PM   #7 (permalink)
Vin63
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My mileage drops like a rock above 70 mph, and the larger tires add a lot of resistance. Do you have any other modifications regarding suspension/lift or tune? I would try running a stock tune to compare.
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Old 02-28-2013, 11:39 PM   #8 (permalink)
johnny6.6
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As alluded to above, if you want better mileage slow down. You're getting 15 at 70-75!?!?!?! AND COMPLAINING ABOUT IT!!?? You're driving a 4x4 truck with a 6.6L V8 and the aerodynamics of a house. What do you expect to get?
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Old 03-01-2013, 01:34 AM   #9 (permalink)
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Re: fuel mileage help

I get 19-20, on Highway. 13-15 in city. Same set up, except not running +2. Running 33" Toyo AT at 45 rear, 50in front. I have the 160hp tune set.
Getting ready to do efi live. Curios to see what that will do.
Cc, 4x4, short bed 2500

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Old 03-01-2013, 12:31 PM   #10 (permalink)
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Quote:
Originally Posted by PEANUTGRWR View Post
I have an 08 lmm that gets terrible fuel mileage. It has a ppe hot+2 tuner on it with the cat, muffler and particulate filter all taken off. its a 4x4 crew cab short bed. on a good day it might get 15 mpg if im lucky at 70-75 mphany ideas or suggestions to improve this? it doesnt seem to matter what setting on the ppe I use, they all suck as far as mileage. I sure wish I had my old lbz back. is there any easy way to make this a lbz with just a ecm chance lol
What size tire are you running. I can get 20-21 mpg on the highway, with my PPE set on level 6. I cruise on the freeway usually at about 68-69 mph, and am very light with my throttle. Around town, I get 14-15mpg. I don't know if my built trans or 4:10 gear is helping me over your setup. I suspect your tire size has a lot to do with it.
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Motor Mods: PPE Hot+2 tuner, PPE ported fuel rail fitting, Banks air intake/filter & super scoop, Banks boost tube, Air Dog II 165 LP, EGR blocked, 5" Flo-Pro DPF back exhaust, PPE Centrifuge, Superflow Dyno @ Westech Performance Group (522hp & 956lbs. torque Hot+2 Race) with DPF & CAT 506hp & 925lbs.torque (Smog Legal once again)
Trans: Stage 3 built by Mike L. (Inglewood Transmissions), with Suncoast 1057 TC, PPE pan, Upgraded trans lines.
Rearend: Re-Geared with 4:10 and Chrysler posi unit, Mag-Hytec cover, Firestone airbags.
Tires & Wheels: 2012 GMC factory 18" with Michelin 265/70R18 LTX A/T 2 with 1.5" adapters by Motor City Bolt On
Interior: PPE EGT, Boost and Fuel rail pressure guages, Pioneer DVD HU, Components, Pioneer 10" TS-SWX251 flat sub, (2) Alpine amps.1988-1992 USMC, 3RD AABN, Desert Storm/Shield Vet
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